I'm running a 68 250, bored .030 over. The head requires 5/8" nut plugs (narrow passage on the head). The distributer is from a 75, electronic ignition, separated coil. Now, with all that in mind.
What plugs and gap should I be using? I found plugs to fit, but gapped them to the 68 standard (.035). Should I be gapping these to .045 (or higher?) because of the E ignition? Currently, the truck performs ok (power), but gets poor mileage (about 12), and diesels at shut off. Hopefully, Chiphead or one of you other gurus has the answer for this one.
Thanks.
