Without cats using and a 5"x11"x22" dual 3" in and 2.5" out muffler (12569)?

Reason being is I found a set of 6.0 HD exhaust (3" duals) from the manifolds to somewhere down the side of the truck and could step up to a larger, more free flowing exhaust...and dump this Flowmaster!

Thanks!

 

I recently took my cats off and noticed a little rasp but it is not real bad but it really got louder though. I have dual 5x8x14s. I am thining of going back to a single 3" 5x11x22 with a cutout to keep the sound down for everyday driving.

 

Do you think the rasp (what little there is of it) will be far less with the 5"x11"x22" muffler vs a ~5"x8"x14"?

Thanks!