since its been determined that the 90 - 92 Formulas with the 5.0 TPI got the good cam regardless of transmission, is it possible to put the exhaust manifolds of the 5 speed 5.0 or the 5.7 on a 90 formula with a 5.0 TPI A/T? Then you would basically have the same horsepower as the 5 speed car, right? or is headers the way to go?

 

Go with headers, the stock manifolds are junk.

 

I agree, the very small power gain you will see with the "better" manifolds won't be worth the time invested in putting them on.

 

As far as I know, all of our cars got the same exhaust manifolds. And they all suck. Why go through all that work when headers can be had for $99? Ok and another $99 for the Y-pipe but still. You get the idea. I picked up .6 and 5 mph in the 1/4 from my headers/y pipe/cat delete plus big SOTP gain and MUCH better sound.

 

No non-G92 TPI cars, LG4 and L03's all got 1 7/8" outlet exhaust manifolds. G92 TPI cars and 350 TPI's got 2 1/4". Unfortunately swapping the two manifolds is not worth the effort. If you're going for a stock look, then it's worth the effort; but if you dont care about foolin the guy next to you, then go with headers. The only stock manifolds that can make power are the old ram horns. And they wont clear the thirdgen frame.