So….more header talk….this had me scratching my head

Les Gibson said

Comp Cams roller, gross lift .654 intake, .655 exhaust, duration @ .050 269 intake, 276 exhaust installed at 106.0 center line.
13.9:1 compression, 5.13 gear, approx 5000 stall with 9 inch converter, edelbrock victor W2 intake with either a first generation 1050 dominator or a Quick Fuel 1050 dominator style carb, I run both. Tire diameter is 31.5, shifting at 6500, trap rpm in the 1/8 is about 6700, 1/4 around 7000. These trap RPMs are a best guess as I can't recall the exact numbers.

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So I made some assumptions. One assumption is that your cam is ground on a 110 LSA. Another is a 2.08 intake valve. From my guesses you should be on a 107 LSA and probably be installed on a 107 ICL and I think a 106 LSA/106 ICL wouldn’t be bad either.

The other thing I saw and forgot to mention was you have a 7 degree split between your intake and exhaust duration. I know that’s been all the rage for 20 years or so, but I think it’s a bad way to make power. It’s another one of those things that make a header numb. I know Billy Godbold said some intersection things about duration splits and the overlap triangle in an article. I know I have it here somewhere. Finding it…that may be an issue.

I also assumed you have W2 heads. The exhaust port on those is too big, as is the valve. IMO, you need to a single pattern cam, probably 272-274 @.050 and put it on a 107 or even a 106 and install it straight up. IMO, then the headers would have a big effect and the power curve would be fatter off the converter and in the gear changes.

I’m going to look for that article and I’m also going to enter your cam numbers into a really simple program I use and see what it looks like.

Just my opinions on why a header change didn’t make any difference on your engine.