My camshafts of has the two hole disc at the timing chain end of shaft and ID plate in engine compartment reads 4/6. However, several sources suggest Series 2 settings of 12/14 for my 68 E Type. Currently set for 12/14 and runs well until 3500 rpm when engine backfires and loses all power.

Comments?.
Thanks

 

Just answered another post on this same subject. I think I'll have to delve into one of my Paul Skilleter books. There was a change of camshaft profile which forced the clearance change, but not sure when it was. If your engine is the 1968 original, I'd use the original clearances.