Bought a bunch of these in the early 80's (about $50 each) and saved them as my retirement projects. All I can say is that on a dollar to horsepower calculus, it is very hard to beat for a good street engine!

I've built 13 engines for my monte carlo and the 400 was always the best bang for my buck. Holy shit those engines have so much torque they can break a neck.

I built a few different 350s for my 80 Malibu in those days and they all ran very well, but the 1st time I used a 406 with 12.5-1 compression it broke the 7.5" 10 bolt immediately.

I heard that stuff about the 400 rod length forever, thanks for a definitive answer. SBCs Forever!

So happy I built a 406 for my vette! 406ci SBC Scat 9000 10.5:1 Probe Pistons Eagle Rods Protopline 235cc Heads .545in/557ex. 244/248 @ .050" 106lsa RPM Airgap Holley 750 3000 Stall Turbo 350 basic rebuild/shift kit

I've been building 400s for over 30 years. People dogged me at first, telling me all the horror stories, and why it wouldn't work. That soon changed, and people started showing respect for the small block that was giving many big blocks more than they wanted. My experience has been the 400 likes big heads and more cam timing. Rod ratio makes no difference. I believe Joe Sherman said once that the "rods connect the piston to the crank, period". Great engine for a street machine in my opinion. Power of a big block, with the weight of a small block.

The only small block I ever used for my drag car. They are excellent. My first hotrod got a 400. Back in the 80's smoked every small block car I ever went up against and several big blocks. Most of them that I used were built with the stock connecting rods. I got into the 11's na with one completely stock bottom end, a set of camel hump 2.02" heads that I home ported and a smallish solid flat tappet cam. This was in a 3300 pound car. There was plenty more in it but the car was stolen before I got the chance to really get it optimised. Its one of my favorite engines of all time.

We learned of the 400 small blocks down south from the dirt trackers and Sportsmen drag racers in the early late 70s early 80s. Ran a 64 Nova station wagon with a mile 406 and 373 gears on the street in the early 80s, most fun I've ever had with a car! 400 small block best bang-for-the-buck.

Great content Richard. I build engines and I wish I could convince my customers of the point that you just proved. One engine, unlimited possibilities. Mild to wild. Thanks again, Ed M.

I have been running the 400 SBC since the late 80's, the short rods were never an issue until you started making real power and they started to become a problem, either way a fine engine that has served me well for a long time.

A friend of mine built a 400 for His 70 Nova. After He drove it one time, He said He would never build another 350.

Here we go! THIS is the test I have been wanting to see. Gonna go ahead and give it a thumbs up and make some dinner then watch it lol.

I've run 400 sbc for the last 10 years, current setup is 400 30 over 5.7 rods h beam eagle crank and rods , heads are ebay 200cc runners 64cc chambers 11:1 pump gas flat Tappet 535 lift howards cam. Runs 11:50s in the quarter in my s10.

Arguably the best small block I ever built was a 400 .030 over with a forged 350 bottom end. If I remember that produced 377 cubic inches. It was for a dirt track stock car. Rules said it had to have flat top pistons and a 2 bbl carb. Holley 500 cfm 2 bbl was legal. And a stock cast iron intake of any gender. So of course I had a 4 bbl intake. I put "double hump" heads on it with 2.02 intake valves. And some porting was utilized but mostly just gasket matching the intake with the heads. But the secret to what I did that no one ever knew about at the track was I angle milled the heads from zero on the intake side to .120 on the exhaust side. If I remember correctly this raised the compression up to around 10.5 from 9. It was back in the mid 80's so my memory is not for sure but I do remember how good that thing ran for sure!!!!!

I remember my cousin's nova with a 400 sbc 40 years ago. Stock motor but it had enough power to break the rear tires loose without side stepping the clutch!

I just recently bought a stock 400 SB. It has all factory pistons, 5.565 rods, and crank. I'm going to put twin 76mm turbos on it and an Elgin 224/224 @.050, .466/.466 lift, 114 LSA cam, and ported 882 heads.

Used to street race a couple 406's back in the day....loved them engines!!

The 400 is king of the small blocks. Great video Richard.

Great video Richard! 400 is my favorite SBC. My uncle and I built two of them. One for his 69 Camaro (replaced the stock 307). And the other for our farm/street stock pulling truck, a 1967 K20 with SM420 and Eaton axle w/4.56 gears. Both motors got double hump heads and ran great!

I had AFR 225'S on my sbc 400(.060 over) but they are off in anticipation of a new set of $10000 Billet heads on order now. She's a screamer already in my sleeper 1979 k20 AWD Silverado. I have destroyed the ego on many a big and small block. When real competition steps up, I tend to go to the track. Everyone else gets beat to the speed limit, as they finally speed past me going faster than posted speed limits. No tickets in my back pocket, lol! I really don't cate if I get beat. It's all in horsepower fun. Love my sleapers.

Personally dealt with a 400 with the "junk" short rods. With some max effort ported 461s with 1.6 rockers, flat tops, and a comp 294s it was a running son of a gun. It motivated the short bed 4x4 it was in very well.

My off shore race motors from 1970 are 427 tall blocks stroked. Love that long stroke.

The 400 with trw flat top pistons, good cam and decent heads is a street beast. Had one in a 68 Camaro would run 6.90's all day long on motor then drive it anywhere.

Thanks! Was going through withdrawals from not having my daily dose of a Richard Holdener video.

My brother has a 72 Caprice with a 400 SBC my parents bought new. Story was it was ordered for the police department as an interceptor but they backed out from lack of funds and the car was sold at a discount. It has a factory iron 4barrell manifold and I don't know what else but I know that car would flat haul. Geared to the moon it would go well over 100mph in 2nd gear. I don't know the top speed but the speedo will go past the 120mph limit mark like it does the 80mph mark. The suspension on that tank at 120+ makes it feel like you are just floating and hopeing the road is still under you. The guys that raced those things in the day 200mph were nuts! lol

Engine Master's Jon Kaase; "run rods 2" longer than stroke". In the 80's I took a 400 added Brodix Heads 2.08 int., cam, etc. installed into a 69 XKE Jag. raised the gear ratio to 2.88/1 with a 4 sp., used only 2 gears ever, start in 2nd, immediately shift to 4th. Never had it on a dragstrip , but with the independent rear it was pretty much unbeatable on the street at 2300 lbs. Of course never tangled with a like style street rod. Should have never sold it, wish I could find it. Red, IROC chrome, no holes in hood (bonnet).

Thanks Richard thats what a was asking to see and u delivered i 400sbs my first camaro had one in it and my fast car had one in it lol by far my most favorite sbc

It works for me. A mechanic friend that kept my big truck going well built a 400 and put it in a S 10 and went to drag racing. Well, he had to have it inspected all the time and the officials would ask him what he had done to it to make it so fast and he said he said he just ordered a kit and took his time and put it together and that was it. Well he had all the safety stuff but after his first season they told him before he started the next season he would have to have a parachute. Apparently it was very fast. As they say, whoever they are, "There's no replacement for displacement." Excellent video.👍

Thanks to a Switched on friends advice, who was still an apprentice mechanic, (who believed you should not look at the HP an engine makes but the foot pound of torque, going no higher than 5500-6000 rpm for the street). So in 1989 I was one of the first if not the first to run a 400 Small Block in Adelaide possibly even Australia. It had Forged Flat Top TRW Pistons, Stock heads an LT-350-HP cam and an Edelbrock Dual Quad manifold with 2 Carters on it. It cost me $4500 and produced 210k/w @ 4500 RPM at the rear wheels. we couldn't push any further as my 55 Chevy was losing traction. To the disbelief of the mechanics who literally said 'What the F*ck is in this". Why? The day before they did my mild little 400 they had a $7500, - 350 built by one of Adelaide leading engine builders who told me not to go for a 400 and run a 350, and his 350 produced 210k/w at 7000-RPM. (but i guarantee you i had more foot pound of torque than his engine did). Needless to say my cheap mild little 400 destroyed everything on the streets of Adelaide for over 4 years. and believe me when i tell you this, they were all $7000-15,000 engines. Big Blocks and Small Blocks. i would push my 400 to 5500 rpm, slam the powerglide into 2nd and she would slingshot my 55 into another dimension. The 400 S/B revolution didn't come till 4-5 years after i had mine on the road. As for the short rods, no they don't make any less power, from what i am told they simply limit you to a comfortable rev range of around 5500 RPM, if you are building a 400 it's best to use the 5.7" rod (which they have had for a while now, as they produce less piston friction on the bore). as for the factory used 4 bolt 400, I was told a while ago that they do have a tendency to crack around the bolt holes under pressure, and that the 2 bolt 400 was actually stronger. so if you are looking to supercharge the engine an aftermarket block is best. "anybody who chooses a gen 1 small block smaller than a 383 or 400, is living in the dark ages, HP means nothing as there is no substitute for foot pound of torque.

Ive gotta say...what a well researched article. Thanks for telling everyone who querried the 3.75 inch stroke. Bang on regards the rod ratio on a good breathing 400 Chev small block. Finally some justice in the SBC world!

I originally was looking for a 400 sb to build up with a stroker kit but couldn’t find a good core that wasn’t cracked. That was around 2002, I’d go aftermarket nowadays but went stroked BBC . Great video!

Had a 400 in my 67 Chevelle drag car. Ran Doug Herbert cam, dart heads, victor intake, dome pistons running 13.5:1, and ran alcohol. Ran 5.90s in the 1/8 in a all steel body car. S

I don't know why everyone is drooling over 383 strokers, when they can just build a 400, especially on a low buget build

As a Ford guy I owned a 72 c10 with a built 509 block 400 it kicked ass!It made 425hp and 500ft lbs of torque ran ICE cold and ran HARD!!

Rewatched this one because I had a SBC400 in a 72 Impala. To put it in perspective the 327-365 made about 355 hp on the dyno. That works out to 1.08 HP per CI. A combination capable of making that same 1.08 HP/CI would make 432 HP on a 400 SBC.

Love that 400sbc! When I was younger back in the 90's, we ran 1/2 ton 4wd 81-87 Chevy trucks. The first thing we would do is build a 400 and swap out the 305/350's. We abused the hell outta them and we never had any block problems. We did however blow a bunch of transmissions and rear-ends.

I also used a 400 block to build a .125 over 302. TRW made the pistons back then and the pin location was to use 302 rods and crank It had overheating issues too but it was a drag engine. It wasn't a idea build because of the extra machine work special main bearings and have it balanced

I have done the newer “Dart & “Blueprint SB 400 & they are a Beast with the right Rotating Assembly, Cam & Heads

Love my 414. Offset ground 400 crank with 6" 350 rods. More cubic inches.

Glad to see you do some 400 testing. I know the ls stuff is the easy way now but the 406 to 434 has always been my go to. Old school with nitrous 🤙

In the 80’s I ran a mildly built 400 in a Monza. It retired with 0 losses. I had good heads, exhaust, and cam. Struggled with engine temperature the entire time.

Great video and that output was all nonintercooled. Intercool for lower charge temperature and fuel injection for a Big Bang SBC 400

Hi Richard, I built a 400 from a bunch of stock parts I had laying around about 15 years ago. It started life in a '76 Laguna S3, I used a set of Vortec heads (906), a 268H Comp Cam, a set of TRW forged pistons with the relocated pin hole and a set of PM 5.7" Vortec rods. Topped it with a 800 QJ on a Weiand manifold and the only machine work was a port match and decking the block and heads, only major parts bought besides the usual was the pistons. We stuffed it into a '69 nova that belonged to a friend, OMG. I had a 76 Camaro at the time with a 454 and Turbo 400 and he made it a point to embarrass me every chance he got and rub my nose in the fact I had built the motor. I had to step up my act with one of the first LS's I built at the time but no one would believe it was a 400 in that Nova. Was it the longer rods that helped that motor run so well, maybe the heads, just got lucky on the combination ? Who knows but I still have another cast crank 400 short block sitting and with the cost of SBC parts lately maybe a new build with a turbo would be interesting but I can attest to how much power those engines can make.

Back in the early 80's we would pull the 400 4 bolt 4 barrel motor out of a Kingswood Estate wagon. I don't know why, maybe the life of slow pulls seasoned the block, but with a good cam, intake and valve job these things were awesome in a light Nova or Vega.

The small block 400 was always my favorite small block, I had a few of them and just a cam swap would wake those motors right up, beat up on any other similar small block I raced against, it was a lot faster than my 302 HO big roller cam motor with TFS heads and a victor junior intake, Holley 650 double pumper, that was a huge disappointment

Always been a fan of the 400. Thanks.

I put a 400 in a Chevy Monza for a friend of mine. It was just a stocker and it was plenty hairy. The torque was marvelous.

There's a local guy that bought a restored short bed mid 80s c10 square body equipped with a moderate built up roller SBC 406, I was told he bought it with the intentions of doing an LS swap for that next level performance but after a week of driving it around he came to the conclusion that definitely would be not necessary because as people say " just an old smallblock" was way more than adequate... I love that stuff and as much as I respect LS based engines it would be cool to spank an LS swapped truck, just because I love an underdog and because the folks that rip on the SBC even tho they are one of the greatest engines of all time with run of over 40 years....it's not the best design obviously but still has very high power potential no other platform has or ever will do that again. Also the idea engine gurus are building hybrid engines of basically and LS with SBC short block architecture claiming it's definitely superior.... Huh.

I agree!! My 355 with wieand 177 10.1/2 to 1 hydraulic cam with the 2.5 upper and a 7in lower and a hundred shot of nitrous made my truck run 970. Now I have a 406ci with the same wind 177 supercharger solidcam no aluminum heads yet that makes a shit ton of power. What idk yet but the 355 made over 600hp to the wheels

Would like see some high low end torque 400 vs 383 vs 350 be great to see how they come out

I love, Love, LOVE! A 400 small block!!

400 shootout,chevy,ford,dodge.Of coarse my favorite would be a AMC 401 but finding one is the trick.

I really enjoyed the fact that someone decided to cover the SBC 400. However, there seems to be almost no budget with this build which makes it hard for the average Joe to relate to.

When i think sbc i think 400. I built a 406 for a k5. Nothing fancy, reused the rods but polished them, had 10:1 compression with a set of mildly ported aluminum l98 heads, wieand stealth intake and a decent comp cam. It had instant torque and was very powerful. It pulled like a champ.

Glad I snagged one 15 years ago. Damn dirt track dudes!

Was waiting for this test! Had a 400 Sb with fuelie heads and a mild cam. Tall gearing because it was a high car and that motor still pulled strong. Then spun a cam bearing and would loose oil pressure at idle. No over size cam bearings for 400 they said.

I'm glad I watched this video (I watch all your videos). I have a new Bowtie block I found on Craigslist a few years ago. It's the one with the 3.97" bore and I was planning on using it when I rebuild my '68 L69 327. Since I would have to get the Bowtie block bored for my new .030" over 327 pistons I decided after watching this video to "go big" with the Bowtie block and have it bored .125", get a good forged 400" crank/rod assembly, a good set of heads (probably AFR) and solid roller cam. I'll rebuild the L79 with the original block so if decide to sell my EC in the future I'll put the rebuilt 327 in it and keep the 400" motor.

Great video....very informative...thanks rich✌

Great video bud, we have a 400 in my son's nova and it's a beast. 👍

Here's the 406 SBC I built a few years back for my -67 Camaro grocery getter : - 400 SBC block from 1976, 0.030" over - Milodon splayed main caps (center three), ARP studs - Eagle forged crank, Scat Pro Sport H-beam 6" rods, SRP Pro Series pistons. 10.2:1 CR - AFR Eliminator 195cc heads, street port, ARP head studs - Comp Cams Extreme Energy 282 hydraulic roller cam, Howards lifters, Comp 1.6 Pro Magnum rockers - Edelbrock Performer RPM Air Gap intake, 750CFM Holley double pumper, 1" HVH spacer - HEI distributor, Pertronix coil and module WIth a TH700 tranny, 3.55 rear gears and 3650lbs weight, I ran a 11.34sec/120MPH quartermile.

Boost and a good flowing head.. best of both worlds! Love your uploads 🇦🇺🤜🏼🤛🏼😎🍀

I'd sure like to see more 400 builds there getting alot harder to find and when u do they usually want alot for them in good shape.

thanks for this video Richard! I am planning on a Dart block with 350 size mains.

One thing most people don't mention, is by running e85 you can eliminate the need for an intercooler. Making turbo lag a lot less of an issue. However it takes almost 2 gallons of r85 to equal regular gasoline. Mpg not so good. Bloodviking

I was waiting for a 400 sbc so id have a reference for mine

With all the awesome 400s available (for a bargain) from Blueprint Engines, or build it yourself with a Dart SHP block. I'm not sure you could take a junkyard 400, add aluminum heads, forged rotating assy and machine work for what you can buy a BPE 400 with all the good stuff and a warranty. Unless you're limited on cubic inches for some reason, I don't know why you would buy anything but a 400 in a SBC crate engine. The 400, the original "bored and stroked 350!".

We never had rod issues in the 400... We had axle issues and pinion gear issues and torque converter issues...😂 Still love this video

Great analysis RH! Thoroughly enjoyed.

Buddy had a B&M Mega Blower on a 350, put the cam and heads on a 400 and shaved a full second off in the quarter. Both were stock blocks with factory pistons.

A lot of people don't like the 400 because they feel it didn't make any extra power. But power is in the cylinder heads. A few rare 350 and 327 did have heads that were better equipped. Big intake valves, guide plates, screw in studs etc.. And that's a little better place to start. But with good heads and healthy cams they are beasts. Much bigger and it's hard to get the specific torque to be the same but you may still see gains in total torque or better idle quality but I don't think it's worth the expense if you have a 400 short block.

My brother had a built 400 in a 85 firebird its still the hardest pulling car ive ever rode in

Awesome comparison, Richard. You bringing up the OEM vs. Aftermarket block question addresses my question. In the rust belt, the trucks rotted away by the nineties, mostly. Circle Track racers scarfed most of the production blocks years ago. I always heard contrasting things about plugging the steam holes in the block deck, vs drilling heads to accommodate them. It seemed like guys took the 400 crank to make 383 ci engines, then circle track guys would buy the cracked blocks, spray weld the decks, then put 350 cranks in them for 377 ci.

The 406 was the hot setup in the late 80s and 90s. The problem now is that stock 400 blocks are scarce. You have to go with an aftermarket block and that's expensive.

Great video! Nothing like good old 400 sbc!

Once again boost for the win, the 400 with an aftermarket block is a killer combination in many forms

SBC Dart Little M 400 cid, Dart 215 Platinum Heads, Probe Pistons, Scat Rotating Assm. with 5.7 in. rods, Crane 118751 Mech Roller Cam, Chevy Bowtie 10051103 RR Intake, Holley Competition 830cfm Carb, Crane Cams Gold Rockers. Made 640 hp on an ez tune, the power band is sweet!

In the early 90s we're running 406 377 for everything from Circle Track to drag racing

Yay, a 400 video. Ive got a 400 w/twin 72's and a CSU 750 that runs pretty good. I'll prob switch to LS when I blow it up but it never blows up!

Ahh this is one of the engines I really wanted to see, great stuff

Hard to find, a used 400 sb, these days. We loved them, when I was growing up! Drill, the steam holes, in double hump heads, combined with a good camshaft. The 400sb, would wake up!

Sbc 406 my favorite,,,

Smal block 406 chevy is brutal! I built a short rod 383 one time ..550+hp and 520ish tq street motor.

You’re saying, the small block 400 doesn’t stop at 5200 because of the Rod length, It’s because 194 don’t flow enough for 400 in.³

richard. YOU ARE MY HERO !!! Holy cow, you are a BEAST !

Hey Richard you should do a video on the small block 305 budget build.

Just got a small block 400 from my brother who went LS. Thinking of bore and stroking it into a 434.

the rod length has more to do with efficiency is what i've always thought about. meaning, how much stress it places on the block: pressure on the block wall, piston speed, etc.

I think it would be cool to see some twin charged stuff, roots or twin screw with a turbo blow through or roots with a centrifugal supercharger etc

A little 400 love... I like it!

I have a 400 from a delivery van sittin in the garage with like 40k miles on it. Not a chevy guy but would love to get a 70s or 80s caprice wagon and make a big ol grocery getter sleeper.

Excellent video. Hey Richard, can you do a roots blower test where you use Premium pump gas/Race gas/E85/Methanol to show the power differences and potential of each fuel as well as the discharge temps? Maybe use a decent blower like a stripped Littlefield.

Factory block would not have mattered or influenced hp/torque readings. Aftermarket blocks offer a lot of advantages over stock blocks particularly under boost or higher compression ratios. I know preaching to the choir. Lol. Good test with results as expected. I so enjoy your videos. Always informative, always practical, well thought out engine combinations. Thank you.

Love the content but my local salvage yard is as likely to have a Faberge Egg or a bus full of cheerleaders break down in front of the main gate as they are to have a 400 small block. They were rare and hard to find 20 years ago.

Thanks so much Richard I love your channel.

I thought you were old enough to remember smokey yunick and joe sherman but I guess not. First Smokey did extensive dyno testing back in the late 60's or 70's and he found he could make more power with the longer rods. Once he let that out the rest is history. Circle track magazine repeated the test and they got the same result. Here is what my take on what they were getting. These first off were motors that met certain stock car rules. Second point was that piston speed at tdc is slower with a longer rod and piston speed was slower for the short rod halfway down the stroke. Third point is the short rod creates more side load (due to angle of the rod) against the cylinder wall. The motors that would make the extra power had restrictions on the top side and the slower piston speed would allow the cylinder to get more a/f into the cylinder and make more power. These restrictions that Circle Track had was a 2 bbl carb and smog heads. Now if you think there is a magic gobs of power here forget it. It would have been enough to make the difference of winning by 4 ft. In other words about 10 horsepower and torque. Now the big problem with chevy 400 block is because of the Siamese cylinder walls didn't allow it to cool correctly in truck applications and they would have overheating issues if you didn't watch the temp gauge and once you over heated the block it was down hill sledding from there. Second problem was because of the side loading of the short rod and blocks running hot this motor was more difficult to get long life out of them. Joe Sherman used to build these all day long with low 500 horsepower back in the day. Then everybody started doing the 351W to 400 strokers. Joe tried one of them and was shocked how easy it was to make the same power so he dropped the chevy did this for another year and I think retired. For the record on a 3.5 stroke chevy ran a 5.7, ford ran 5.78 - 6.25 rod length, and chrysler ran around a 6 inch rod length. With no restrictions all those motors make the same power if you build them so they all get the same a/f in the combustion chamber. Assuming machine work and spark are equal.

It's only cheaper to use a 5.7 Rod well it was back when I built my 406.... To get pistons like you were saying Richard in the Odd 5.56" wrist pin hight was like pulling teeth! No one has them in stock for anything more than stock replacement cast dished slugs. Trying to find forged ones in the 5.56 was about another 150 bucks in the cost of the set of pistons between those custom ones and off the shelf ones already made to utilize the 5.7" rod. So I changed the rods out the only issue was the rod bolt heads needing clearance for the camshaft lobes in the 400 with the stock stroke of 3.75" aftermarket rods and even stock rods with a larger cam profile comes into contact with the rod bolt head's. Grinding the bolts was the only bitch and trying to not lose too much balance between the 8 rods. Otherwise with a cast crank and a factory block I hit well over 8500 on more than a few occasions accidently when I didn't have the rev limiter setup. Never hurt anything inside but oil windage is definitely a issue with the stock cranks and a higher volume oil pump! Ended up pulling the pan and going with crank scrapers a stock volume pump and a 2 qt larger pan. Made a great difference in parasitic drag and no more issues with oil foaming and oil pressure drops at 1/4 mile runs. Hope this helps someone who has this issue? My oil pressure would drop off about 3/4 track and continue falling until the finish line all due to the oil whipping into cream inside the block.

YES! THE OTHER SMALL BLOCK! 400!

There's Something also to be said about the "400" everyone seems to overlook! The fact that it's a much stronger casting due to the Siamese cylinder bores and more stable crank with its larger mains than a 350 or 383 stroker the 400 can withstand higher cylinder pressures without deflection as does the crankshafts with its larger main journals. All in all its in its own place when it comes to a SBC Period! It's been engineered via the factory to withstand much higher torque numbers than that of a 350. And NO they don't run any Hotter than any other SBC due to the Siamese Bores! Biggest pile of BS ever talked about was they overheated easier and ran hotter than any other SBC! Bullish-- I run 180℉ all day long on a 90+ degree day with nothing fancy for cooling systems! And no he's absolutely correct about rod sizes! The 5.56" VS a 5.7" Rod makes absolutely no difference in power or reliability, it's just cheaper to run pistons drilled for the more common pin heights like he stayed. I changed from the stock length to a 5.7 for an H beam rod and realized the pistons were at the time almost 100 dollars cheaper than a set for a 5.56" rod. That's the truth, I have a 406 that's is right where he's dyno'ed his at NA 575Hp at 10.9:1 with Cantfeild Aluminum 2.08 In & 1.65" ex valves and can get away with premium pump gas, unless I know I'll be racing it! Then it gets a mix of race fuel otherwise flawless powerful engines!

I’d like to see how much a 400 with at least stock block and crank could handle...

The thing that always steered me away from a 400. Wasn’t that rod ratio but the fact that I always heard that the stock blocks were inconsistently made and a lot of them had thin cylinder walls. This is also way back before a lot of economically priced aftermarket blocks were being made. Which brings me to my next answer. Yes. Going with an aftermarket block for this test was more than worth it.