So of course I'm new. Can someone tell me how to identify whether my engine be a non-rev or rev-up. Particularly stating in a manual preferrably. A little confusing. And if I do put a 5/16 spacer on will it cause my engine to run lean? Thanx.

 

rev up engines are on 05's and 06's. if you are still not sure, look through your steering wheel and see if you see the word rev in the instrument cluster.