Quick Question guys. I got a pair of i beleive edelbrock shorty headers on my 350. Well i need a hole new cat back. Right now the headers come into a 2" y-pipe into a single 2.5" converter and into a por-flo muffler. I want to change the the cat back to american thunder which i believe would help alot(considering right now i got a shot muffler and a clogged!! converter. prolly losing 30-40 hp). But im wondering if the y-pipe is way to restrictive. and if so how could i run them so there not and keep it under 400 bucks any suggestions are really aprreciated

 

The 2" y-pipe is not your biggest worry... the combined pipe AREA of BOTH sides of the y pipe is 6.45 inches... a 3 inch pipe (the cat-back) has an AREA of 7.06 inches... that's not that much of a difference... If your y-pipe is TOO much bigger than 2" per side you WILL lose too much pressure and by the time the air gets to the cat (even a new one)...bad flow again... you DO need a HIGH-FLOW cat or puch it out... that's what'll kill ANY exhaust... GOOD LUCK