318 wont rev above 5,300

Prine said
hmmm...irrelevant advice, or too lazy to pull the plugs and regap them?

I may not be able to figure out how a Tuff Wheel horn button actuates the horn switch, but I KNOW turbocharged engine diag.

I agree. Sounds like spark blow out to me too. I had to bring the gap down to .025 with 10# of boost, stock ignition, and autolite plugs.