OK, thanks again guys.
Ed, I really appreciate the detail you provide, including the group numbers.
As a side question, what is the basis for the different sized harmonic balancers ? i.e an 8 inch dia balancer for the L48 four barrel engine and and a 6 3/4 inch dia balancer for the 2 barrel version? I assume there is a difference between the rotating assemblies, and thus a different sized (mass) balancer is required. Perhaps it's the crankshaft used that determines the balancer required ?
Also, not to be overly abusive with asking for help, but GM part numbers for '69 L48 for the following would be very much appreciated:
Alternator upper bracket
Alternator lower bracket
Alternator spacer with tab
Clip for holding Negative battery cable onto the upper alternator bracket
Thank you very much for your assistance.