i'm investigating right now for a cat back system since I can't change my R18 sohc. I was wondering if I need a new high flow cat, if I do, where do I find the 90 degree adapter to bolt it to the block. If I don't need the high flow cat, what's the width of the end "on specs" cat as I want a 2.5 in back cat exhaust system.

thanks for the help!