I have a pretty nice header that has four long pipes that comes down to a huge single pipe under the floorboard.. This is NOT a shorty... Does it really make a large difference in performance? I have noticed that the 20R motor really does not like to rev much and always feels like its either restricted or constitpated.. I recently put on a free flowing modern catalytic converter.... Should I put on the header as well? I just passed smog so the air pump is not an issue for another 2 years.. Would I be defeating the purpose if I placed a quiet muffler on the back?

Thanks!

 

Bump for another looksee..

 

if your 20R doesn't like to rev, something's wrong. either the valvetrain is worn out or your intake/exhaust is restricted. this engine didn't come with the greatest of either, but these engines will wind up to 6k in stock form without too much trouble. a header with a good exhaust will most definitely give you a gain in high end power.