i have GTP stage 2+ heads and a T Rex cam in my 02 SS. through FLP 1 3/4 headers and loud mouth exhaust it made 462/402 to the wheels on a mustang dyno. because of a road hazard that i hit i had to replace the headers, etc. Now i have QTP 1/34 headers which lead to two dynomax bullets dumped. no x pipe,etc. i had my car retuned tonight and i lost 6 hp and 9 tq. i know thats not substantial but now im not even clearning 400 rwtq.

i was told this was due to lack of back pressure, and also due to the heavier springs i just put in the car ( comp 921s...the t rex broke one on the crane duals that were in there) so...456/393 rwhp/tq...are these still good numbers? i see people making 470+ hp and around 420 tq...any suggestions? i am thinking about getting the TSP true duals system if you think that would help