Well first off i'd like to thank everyone for there responces to my last post about the heads and all that (you guys know who you are...thankyou)...but now if i may.. i'd like to pick at your brains again...i have an SLP catted X-pipe and LM2 cat back installed on my car...and i am looking at completing the exhast with a nice pair of long tube headers from slp...i see that they sell 2 kinds...1. 1 3/4 inch headers for the 4 valve 4.6 mod motor (03/04 -mach1/ cobra)...2. 1 5/8 inch headers for the 2 valve (99-04 GT) engine....now i know there is only a 1/8 of an inch difference between the two...but if i wanted to (lol) what would stop me from putting on the 1 3/4 inch headers on my GT motor? any negative effects? i seriously doubt an 1/8 of an inch matters either way....but the more flow the better (at least this is what i have been told)...and as before...any feedback would be greatly apprechiated....thanks guys!

 

yeah, the lack of exhaust velocity would actually reduce the most hp you could get, and smaller primaries like that is what you need...your not pushing a large amount of exhaust to need that much room...they do test all the time and bigger is not better, it'll throw off as much as 10 hp...so i think 1/8 that'll net you 10 is worth it

 

well that solves that.....1 5/8 inch headers it is...thanks for your quick feedback....i think i might just order them now..[sm=badbadbad.gif]