jay_c3

I have a 1975 corvette with craite motor and HEI ignition. The corvette shop manual saids to gap at .035, the tag on the car says .060. I gapped the plugs to .045 I think .060 is too much. My other 350 motors with HEI were never spec to .060. anyone come across this?
Also its a pain to replace the plugs and plug wires, so far i got the front two plugs replaced.

Mark Riles

The shop manual and the tag are only reference when the stock engine is in the car with stock configuration and stock plugs. Since none of that exists anymore throw their numbers out the window. I usually will gap the plugs based on specs give by the plug manufacturer for the specific application. Most plug manufacturers have a tech line. Call them and tell them the application and they will not only verify you are using the best plug but they'll give you the appropriate gap. All other things considered, .045 is a good gap to use until you get a more solid number.

Paul L

You will be fine at 0.045".