Hello!!
First time posting on here
Just picked a a '69 Hearse with a 472.
Wondering what I should sent new plug gaps on considering it has a updated HEI
Thank you for any help
Isn't the setting with HEI something like .060"
Bruce. >:D
It depends on the year of the vehicle. It varies from 0.035" to 0.100". Changing the plug gap had more to do with emissions than anything else. I run 0.45" plug gap. This decreases the stress on the coil and module and will fire your plugs just fine.
There wasn't a factory high compression engine with an HEI from this family so we can't cheat and just use those numbers. 45 is probably a reasonable guess. Have you done any research to make sure its a 69 motor? Maybe at some point someone swapped a whole HEI motor in rather than just a distributor. 68-69 were a different casting number than 70-76 so that would be one clue. We had a case here not too long ago where there was a 368 in I think a 69.
Block numbers is a cast in number on the top of the bellhousing flange by the oil pressure sender. It would be slightly to the left if you were standing in front of the engine. 1486238 is 68-69. 1485200 is 70-76. 1609110 is 77-79. 1615255 and 162734 80-81(5). If you want to post some pics with the air cleaner off there are other possible clues to the year also. Nothing is a sure thing since most of the parts interchange so you could have a frankenmotor but if we see several things that point to an HEI era motor chances are better that it is one than isn't.
I will snap some picks. Title and previous owner (whom I know) say 69
Thanks for the help
The first HEI came out on limited applications in 1973. They were not available across all GM platforms until 1975. Therefore if engine is pre 74 or 75, someone has installed the HEI. Just make sure that the B+ from the ignition switch is a full 12 V.when cranking and running. Point systems used either a ballast resistor or a resistor wire depending on the year of the vehicle.
Its certainly possible they just swapped the dizzy but its worth a few pics to see if anything else looks out of place. Could save some time and hassle down the road knowing its probably a 69 or that its a later engine.
I also know a stock HEI will run fine with the resistor wire still in place so if you are not having issues I would not worry too much about that. Especially as these things age its better if the resistor isn't there but if you are having age issues the resistor wire likely isn't gonna be your biggest issue. The wire is easy to identify on the RWD cars because it runs most of the way to the coil and looks different than regular wires. Eldo it splices to regular wire in a big loom so its harder to find and identify.