Checked firing order of plugs on distributor cap, it was right. Moved the all one tower over clockwise, will not start. Same as before. Going back through this thread I read the spark plug gap is .035, I have .046 in there and they are not adjustable, fixed gap. Could this be the culprit? Bigger gap takes more voltage to jump?

Jimmy Deveney
‘66 GMC 3/4 ton pick up
4 speed manual
305E V6