May seem like a dumb question: What size are the plug wires on a GTR-7mm, or 8mm? I've tried to measure mine off my '67 with a metric bolt measuring tool: wire is just a hair too tight to go thru the 7mm hole, and a bit loose in the 8mm hole. don't want to waste money on the wrong size. Also, I assume copper core is the way to go?
Thanks in advance!