[M Zeigler]

All,
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.

Thanks,Mike

 

[Tommy the Cat]

Dave Ray who helped design the HEI has said .045. I doubt you would see a difference if the gap were .035 or .055.

 

[DUTCH MAX HEADWORK]

.045

 

[oldcutlass]

.045 and your original timing settings will be N/A due to the timing curve of the HEI.

 

[sampoerna415]

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.

 

[M Zeigler]

Thanks for the answers everyone, I don't get it out of the garage to often, only used for pleasure drives.

Mike

 

[Tom Mobley]

.045 and R45TS or equivilent plugs. TS have an extended core nose, stay cleaner longer.