I have Edelbrock RPM Performer heads on a RB. I had to clearance the head a little with a grinder to get a Holley HyperSpark distributor to fit. I have not had any ill effects from the clearancing. I just took a little at a time until it fit and would rotate. The Hyperspark doesn't have a vacuum advance canister.
I seem to remember an adaptor available in the 70's to raise the distributor above the head, but that was a long time ago and CRS.
74 Challenger, bought it new. In 1978 I replaced the original 318 with a 446 and 727. Mild cam, Jardine headers, and Holley Sniper EFI.
New engine! 511" RB, Edelbrock Performer RPM heads, Eagle rotating assy, Comp hyd roller cam, Doug's 2" headers.
| 
