I am installing a new HEI distributor, new spark plugs also,1972 GMC Sprint, L-48 350., standard ignition called for a .035 spark plug gap, is there any need to change the gap with HEI?, I am using A/C Delco R44 T spark plugs.
Daily driver? Going racing? Hows the fuel in your area? If you are just banging around town with somewhat high octane fuel a 35 gap would be ok and the plugs would last a little longer. What are you looking to do with the car is the question. 8.5.1 compression kinda sucks if all you can get is sh** fuel.