I run headers and the 90 degree adaptor with no issues, and a long filter. A straight adaptor might not give you enough room either (towards the frame)
i personally think that running the bigger filter with the 90 would be better for filtering myself (less filter changes) but i read that the 90 degree adapters really choke oil flow (not sure how true that is) and i thought while im at it pricing out the gasket kit for the 90 mine as well see what i need to run a shorty straight filter...
all good info so far thanks guys!8)
