I said 2 1/4 in the video. But actually it’s 2.5” exhaust.

Great info Tim!

Nice results, great to see real world results. Thanks

Even a crappy header will outrun cast iron manifold anytime. Just add fuel, as wile e coyote would say🐺

Having spent a lot of money on tires since 1979, it amazes me that there is now a competition where people intentionally destroy their tires as fast as they can.

Got just about the same results with my '87 W-150 difference is I used Dakota headers because of collector placement.👍👍🇺🇸🇺🇸

My 81 W250, when I got it had a stock 318 from 1974, 2brl, with headers. Honestly always thought the headers were dumb on it. Few years ago put a 68 340 intake and 600 Carter AFB and tuned it for max mpg. Headers were rusted out so I stuck early 318 pickup manifolds on it, thinking it wouldn't make a difference, lost enough power to feel and MPG! Same exhaust system. Truck has a 273 with new Hedmans now. Went from a header skeptic to a header user. Four barrel on a stock 318 makes a difference too!

You are so correct. I have played some with the manifold and headers in the dyno, and the results are pretty evident. Doesn't matter what power the engine makes, weather it's 150hp or 500 hp. With smallish primary headers, you typically see about 10% gain in peak and low end torque, and 5% peak horsepower in mild build ups. Using the same mufflers and exhaust pipe size with both. I have found that the smaller primary headers give better gains in mild engines. Typical 1 5/8" headers are on the big side for a mild 318, but still a gain everywhere. For something like 200 or 300 hp the rest of the exhaust doesn't have to be that big either. 2 or 2.25" duals will be more than enough.

Good info to know

I was able to buy and install a drivers side cast iron manifold on my daily driver 73 Duster that you recommended about 3 yrs. ago on a question answered video that you made. Easy access to plugs and no burnt wires. Thanks

In my opinion there’s a big difference in power.. My 87 w250 has a stock 2 barrel 318 and it use to be a manifolds and single exhaust.. when I switched to headers and duals it woke up like crazy.. But that’s just my opinion

Ive always got a few more mpg with long tube headers and a small 500 cfm 4 barrel

As I get a tad older, I will go for reliability over performance. I own a 72 Duster with a 69 340. I use the 69 HP manifold. I custom built 2.5 down pipes and exhaust cutouts. When I go to the track for vintage bracket racing, I run a consistent 13:00’s and that’s ok with me with a car that weighs, with me in it, 3,650 pounds. I will never put leaky headers back on.😅

Both have their advantages. Manifolds are great for being quiet and maintenance free without burning up wires and parts nearby. For the street where you're 90-95% of the time under 3000 rpm it's a good deal. No doubt headers work. I've used many sets. My chief complaint now is how expensive they are. I remember when you could get Cyclone, Blackjack, or Eagle for right around $100 a set give or take.. Now $500-700 a set. Nearly EVERY set of headers I ever had needed some modding. With 'A' engines it's really more beneficial. Those manifolds are pretty corked up, more so than the 'B' engines. Your van is a great example of using headers. Why not? It's so easy to slip those in there. It's a no brainer, especially when doing a custom exhaust.

Great info! Whats your next plan?

On engine masters they said headers even out fuel distribution numbers cyl to cyl.

Excellent info. Yeah. It seems like it’s worth the trouble regarding fitting them amidst the torsion bars and steering components. Nice to have come pretty solid confirmation of that. 👍🏼 I’m beyond envious of that van and it’s just awesome to see that it’s in good hands.

I had a 318 in a Dart but with the factory single plane 2bbl intake but a single system exhaust. I replaced my exhaust in the exact same circumstances as you did with 4 into 1 twin system with a balance pipe. I can report the difference was utterly unbelievable even with the stock Ball & Ball/Carter carb. The throttle response, the bottom end torque, the mid range torque, the upper mid range torque, the fuel consumption was so improved I couldn't hardly believe it. If it didn't pick up about 100ft/lbs of torque I'd be very surprised LOL. Next I had made, a custom single point distributor with vac advance and a better curve, that used reliable Bosch 534 points. I had no money as I was a poor first year apprentice mechanic at the time and one of the other mechanics that was a Mopar nut told me exactly what to do and mentioned you'll be very happy with the results for the cost and ease of installation. It was good advice. Made another good improvement to a stock 2bbl engine. The thing is, it went really well on the single exhaust. For a 318 it was great fun first car. I miss that car so very much.

Full length headers wake up everything from a push lawnmower on up 😅

I think this answers a question for the Huevo Ranchero

Great information!👍

I remember in one of my mopar muscle magazine issues it was the battle between stock manifolds with dual exhaust clear up to the largest long tube headers on a stock engine . better flow from manifolds to shorty headers and between shorties and long tubes wasent much if a difference like maybe 5 HP . Also if you take that insulator gasket on the intake and trace around on the inside and cut out that divider you gain up and flow . charlie that has a youtube channel that does flow tests has a video on modifying that 2 barrel intake you have

Nice video tim, keep up the good content.

Long tubes whether intake or exhaust are for torque. Which is what you feel the most.

Headers increase alot of heat under the hood. Problems with vapor lock warmer engine temps. That's with a towing vehicle. Headers open up power. And sound good. But make excessive heat.

Good stuff you’re putting out there,interesting and do it yourself wrenching!

Nice video!

In the mid-1980s, when I was living in West-Central Texas (Ford & Chevy land) I had a 1974 Dodge Dart, 318. I put on headers and dual exhaust, but it still had the factory two barrel carb. It sounded nice but there was no noticeable seat-o-the pants improvement in speed. It took a four barrel conversion to feel like it was doin' something. It was almost impossible to find speed parts for Mopars in that part of Texas, at that time.

Me , a 1998 Durango 4X4 , 318 230 HP stock . I put on shorty headers , a 360 throttle body with shaved lips on the ventury , I did that , a throttle body spacer . Denso double platinum plugs . The truck would do 130 and give me 24 MPG . Headers can help

Nice improvement. You can use the jets out of an Carter AFB / Edelbrock jet kit in your BBD carb.

That’s a cool van

Headers made a huge difference towing with my 318 van

Always picks up! Even over factory high flow manifolds they will pick up!

I've got an 85' prospector 4x4 with a 318 two barrel I switched to a set of Hooker long tubes (only 250$ brand new by the way) and 2 1/2 inch duals with magnaflows and it woke up power wise very noticeably,not to mention it sounds amazing!! Then added a 71' 340 four barrel intake I paid 25$ for and a used 450 cfm Holley I got for 50$ and rebuilt it and put one size larger jets in the primaries and it's like a diffrent truck!! Next step cam sawp any suggestions on that?? I use my truck as a truck but also like to have fun when I want to so I'm not sure what size cam to go with?? I appreciate your videos I've learned alot!

Long tube headers will almost always make a noticeable difference. The cooling exhaust gasses and pulses from other cylinders. Magnify flow.

i got doug thorley headers on mine, SOUNDS GREAT! i got em on a 95 jeep grand Cherokee 5.2 Orvis

Was thinking about headers on my 318/2bbl Dart. More for the noise. So a little more chooch doesent hurt. I just dont want to fight to get them in there.

You may know this great video by the way, would those headers fit on a 75D 100 pick up truck with a three speed manual I’ve heard that headers might not fit with a manual? Thank you.

I have always found that to be true. I have always found mpg went up also if you can keep your foot out of it. The spread bore Holly also makes a difference if you can keep your foot out of it too but has to be the mechanical secondaries. I don’t know why. Could be just my luck or just don’t know how to setup vacuum secondaries for some reason. Nice job on the van! So what was the muffler you got in the end? Was it to loud?

I had headers on a 318 in a '70 Challenger with a 2-barrel and although it did seem to have more starch in its shorts, I still thought it was sucking through a bent straw with the 2-V. I wanted an AFB 625 so bad I couldn't see straight!

My question is running long tube headers into " super single" exhaust. The truck is a w 150 with a mild cammed 318. Your thoughts?

Pretty cool! Another variant, if I may ask, are you running a stock fan, or a clutch fan? If no, I wonder if it would make any noticeable difference on your 60' times with NO fan to rob any miniscule power. Hmm... I like the way you think! Love your videos!

I have a c10 with 350 that had headers and true dual exhaust ( no cross over) Went to a ram horn corvette ( 2 inch collector) with y pipe and single 3” through a turbo muffler and runs so much better By the way the dual exhaust was 2” with turbo tube muffler

Are you running the stock cam? Maybe look at stock 360 2 bb cam. Don't know if 318 2 bbl and 360 2 bbl cam the same specs. If different try 360 2 bbl cam with a 2 bbl 500 cfm carb.

Telling you right now, theres plenty of ways to make power, but headers are always louder than the manifolds are, i run 3 feet of dual straight pipes and its loud, but not tickets all the time loud

👍🏻💯🇦🇺⛽️

I'd love a cam video. I want something that absolutely chops not sure what to do whiplash or purple Mopar camshaft

Just put used\free hedman headers on my 74 charger 1990 360 roller 4bbl eddy on top of and eddy preformer intake excellent throttle response fit was good but bolt access was marginal..just a street car on my 72 dart 318 roller engine I have stock mainfolds to go on mopar cars are not header freindly espicially with affordable headers reduced hex head and allen socket head bolts help a lot I had to use 3 pan head socket head allens to be able to put the headers. on the charger the one good thing with the hedmans on the charger is you can remove the starter with out moving the header.. If its a mini starter... I'm adding my own H pipes and glass packs and exiting the exhaust out in front of rear wheels all tig welded... Theres a lot of pros and cons too headers on a mopar and price of a set of header does not mean the will fit with no issues but atoxk manifolds fit every time. But are very heavy!... And I will not use composite gaskets copper or aluminum are the only way.

I have been running ceramic coated Hooker Headers on my stock 318 2-barrel for over 25 years. I don't race it, I just like them.

I've always gained something even a 273 will.

17 sec quarter?

I just wish it was as easy to put headers on a A body. As it was your van.

Van? Leave it alone just tune it well In the gas crisis neighbor would buy purple Challenger R/Ts for his dailies. Commuted 150 mi a day fwyin Ca FIrst day the 383 came out, in went a fresh 318, Isky supercam blackjack headers, hush thrush and a well tuned 2 bbl Still sounded good spun tires and got pretty good mpg. Drove it when I Was 13

swapped 318 single exhaust in 1985 to open very small headers and e.t. change was over a second. You are showing TRUCK Manifolds which was considered better then Production car manifolds

Is your 318 already rebuilt ? Why stop at just Headers ? If you're going to do Bolt ons, go 4 bbl. If you're happy with the results, get another 318 and repiston it using KB Flat Tops, Hughes FT Cam, Johnson Lifters and 65 cc heads. But if it were me, I'd swap out the 318 for a built 360 for your SWB Tradesman.

Your Asian too? Hmmm oh aging

Excellent video idea! You’ll be spotting mustangs out there in the 1/8th! 🫡

Headers are noisy

I remember in one of my mopar muscle magazine issues it was the battle between stock manifolds with dual exhaust clear up to the largest long tube headers on a stock 318 magnum engine . better flow from manifolds to shorty headers and between shorties and long tubes wasent much if a difference like maybe 5 HP . Also if you take that insulator gasket on the intake and trace around on the inside and cut out that divider you gain up and flow . charlie that has a youtube channel that does flow tests has a video on modifying that 2 barrel intake you have 8:05