Alright your having way to much fun and getting over you head.

I never said there was a flow issue with the catback....alll i said was if you are getting a dp you should get the outlet end to match the catback size otherwise your slowing down the exhaust a little if you put a all around 3" DP on

Example.. When you gasket match the LIM you wouldnt just stop there and not do the heads, because then that would be messing with the flow now.