hey guys i have a 2dr 2005 jimmy and i have a hole in my muffler so i need a new one. local auto parts dont carry them and dealer is around $400+tax so i want to do a custom. now i have measured it all but doesn't make sense first of all about 2" in front of muffler is a 3" flat 2 bolt flange that i would like to keep in system. now my next worry is that i have only 21/4" coming out of the muffler. so my biggest question in has anyone used a 3in3out muffler on there 4.3? or did you reduce back down to 21/4" after muffler? if so did you just dump under body or get a new tail pipe made? and if so is it cray loud or what? and power loss? thanks

 

I had the same problem and went with 2.5" pipe and muffler. I started at the cat though since the flanges were rusted. I used the 3-bolt header collector flanges to make my own for removing the system. It is a lot louder since it's a Cherrybomb Turbo muffler though. There should be no power loss since you are going larger. Some people might claim some torque loss because you will be reducing backpressure somewhat but I don't think it would be enough to notice or worry about.

 

thanks. I think im going to do a 2.5" as well just start with the 3" flange and weld a reducer into it the have a new tail pipe bent at a local shop

 

if you are referring to a aftermarket style,ive got a 3" flowmaster 40 on mine with factory exhaust tip,its annoying loud. Ive got to redo it. Id advise to go with 2" or 2 1/2". last 3 i had with 2 1/4" sounded tolerable. this is the last time i get 3"

 

No matter what size you go with it will all be based on the type of muffler used. I have a Magnaflow on my car and it's pretty much perforated pipe with a muffler shell on the outside. I can see straight through it.

 

That is how mine is, only mine is a Dynomax.

 

I had a 3'' flowmaster with a reducer and the remains of the stock tailpipe too. It was too loud. I now have a gibson cat back system. I liked the sound of the flowmaster better (not the volume though).