I have a 1987 Camaro IROC-Z, 305 tpi, all stock. i am getting a magnaflow muffler, with 3 in. tailpipes. would getting 3 in. pipes instead of 2.5 in. from the cat back help? the stock pipes have the crinkles in it, the new ones would be mandrel bent. I might think of getting new 3 in. pipes from the headers back, but i don't know. I am just on a tight budget that is why didn't get the magnaflow full catback.

 

Benefits will be minimal. The restriction is already upstream slowing flow so there isnt enough gasses in the rear section to effectively use the additional pipe diameter

Save your money for a full kit or build your own upstream

 

thank you

 

I have 3" pipes out the back and they sound and look great.