2.5" exhaust for a modified Hemi??? That baby's gotta breathe! 3" minimum..and like Fred thinks..2" headers will be restricting that motor. Sounds like you need to re-think your whole exhaust system...if you want it to be efficient,and make the power that it should. Best of Luck with it!
That baby's gotta breathe! 3" minimum..and like Fred thinks..2" headers will be restricting that motor. 
Sounds like you need to re-think your whole exhaust system...if you want it to be efficient,and make the power that it should. Best of Luck with it! 
