I have a '76 460 in a class C motorhome and if I recall correctly the cam timing is retarded on the '73 and up 460's. Correct me if I am wrong, but I want a pre'71 timing chain to bring the cam timing back to TDC or advanced back to pre smog.
I'm looking at going with a Comp Cam High Energy timing chain set #3222 which seems to come up for a '68- '71 429-460
http://www.summitracing.com/parts/cca-3222/applications

Any input on the subject will be helpful.