Ok, so I am very slowly building a 500 hp 1994 camaro z28. I already bought super comp headers but am waiting to install due to the fact that I still have a stock cat back. I was looking at the 4 inch mufflex exhaust and was wondering if it is do-able with a currently bolt on motor and slap a tunable exhaust untill the car has more power from further modifications. That way my exhaust would be set for the rest of the cars life.

 

you'll be fine dont worry about backpressure...

 

I have a 3 1/2" Mufflex cat-back system. I choose the spin-tech muffler. Nice sound, but, highly restrictive to flow in my case. It does cut the sound nicely. So, I added an electric cut-out. It's a tight pipe fit over the axle. It helps to have high-flow cats (like a Random bullet type) (97ss 383 - D1) B.