I'm running stock manifolds, stock cats, stocky-pipe and SLP loudmouth exhaust. Instead of buying a new y-pipe i was thinking of putting two cut-outs right after the cats. What size if this can be done? if it can't i what size of cut-out would i need if i were to put the cut-out right before the resonator? and would i gain more this way rather than buying a new y-pipe?

 

a 3" cutout should do just fine. summitracing.com should have them.

 

I'm getting a 3" cutout installed right before the exhaust curves over the rear axle. I'm not sure if it is worth the extra effort to install two cutouts right after the cats. Even though the y-pipe looks like it does not flow well, it actually flows pretty good.