79 - V - 80 cams

[itsacbx]

Hey all, my 79 has some damage to the left hand exhaust cam - the hard facing has degraded . I cannot tell why but it’s there nonetheless. It might be age related from sitting for years unused - the bike was originally a parts box/tote special.
I have a number of sets of cams from 79’s to 82’s and can’t seem to work out how to tell the 79’s from the later cams.
Is there a visual reference such as a casting mark or do they have to be degreed?
Thanks

[daves79x]

Just measure the lobes, the specs are in the FSM.

Dave