I'm surprised the return wasn't at least 5/16. 1/4 sounds on the small side. I'd like to know how it's (EFI setup) is working for you.

Instead of RTV (liquid gasket) you should use some heavy petroleum grease. The gas will absorb it slowly and it won’t effect your fuel performance. The grease will hold the o-ring in place while you align the unit.

Have the same plan. 1/4 seems little small on the first look but I guess it is better than nothing and it just a 320hp engine.

Man I been there with the fuel coming down your arm into your armpit😂 but glad I saw your video, I have a 67 on my channel and have a holley sniper with the returnless unit, just cause I don't wanna run a return line

Where did you buy the new sending unit? I have the same job to do! Thx!

For your return fuel line did you use hardline or did you use rubber fuel line the entire length?

Where did you buy that sending unit with return line?

Get some!