does anybody know the size of collector in comptech header?? the hole where i connect the high flow cat?? i am trying to buy carsound high flow cat, and not sure which inlet size i need. is it 2.25?? or 2.5?
thanks.

also, do i need any flanges or anything?? if i wanna put comptech header and carsound high flow cat?? what about O2 sensor bungs??