Muffler Inlet/outlet Od Question

[WilliamsVMAX]

Which is a better route to take. I am thinking of just replacing my stock muffler on my 6.2L and I am wondering what size is the best to go with since stock exhaust system is 3.5". Is to better to go with a muffler with a 3" Inlet/Outlet or a 4" Inlet/Outlet?

 

Are there any cons of cutting the exhaust tubing prior to the resonator and leaving it as is just over the rear axle?

 

Also what stainless is a stock GM exhaust composed of? I have been looking into DB performance catback exhaust by Corsa and the tubing is 409 stainless not 304. I am guessing with the 409 you will have some surface corrosion. I really like the large tip and of course the price is more reasonable than Corsa itself.

 

Any feedback is appreciated.

 

Thanks