anyone familiar with a "Raven Muffler"?
found this shop that sells them and heres the specs:
Raven Muffler, is a knockoff of a flowmaster, sounds exactly the same. Only one of each

2 1/2" center in/ 2 1/2" side out

2 1/2" center in/out

3" in / dual 2 1/2" out (Camaro Style)

Haven't heard of them before today.

the stock exhaust runs on a 2.5 inch pipe no? or is the aftermarket ones that run 3"

Stock exhaust is 2.5" There is no reason to run a 3" exhaust until you have gone a long ways with modding.