I cant seem to find whats specifically different between a gm afm cam and non afm cam. Like vvt i see has oil holes on the second journal. But afm cams, i dont know, if you had each on your hand could you visually figure out which is which?

 

AFM lobes will have different lobe profiles than non-AFM lobes on the same cam. If you install with standard lifters, you'll have an idle instability and misfires due to variation. I don't know if the difference if very visible. You could probably try measuring overall lift with calipers.

 

What he said! ^^^ The AFM lobes are different and if run with normal lifters will indeed cause misfires as hard-headed folks have found out over the years.