I don't quite understand OEM versus 2.75" are we strictly talking about the two necks that come out of the back of the FMIC? If I am planning on doing nothing more than my current Exhaust (Berk Street- no midpipes yet), Downpipes and Cobb - (going up to Stage 1+ from Stage1). Is there a reason I should really want the larger pipes?
Also- for the 5" versus 7" with OEM versus 2.75-- is there significant differences in trimming required?
CR-V (no turbo,no fun)