Rebuilt the carb. Because it sat with ethanol gas. Changed the plugs, 5224 autolites. It's popping on the exhaust stroke on the right rear cylinder, if I pull the plug wire it stops popping. Idle doesn't change either. I'm thinking blown head gasket between cylinders 6&8?? Find out when I tear it down.

Edit: pulled the pass. Valve cover to check valve parts while running, and I do indeed have a blown head gasket. Oil is a grayish/green color. Cometic head gaskets any good?? I'm surprised these fel-pro ones lasted as long as they did running 11.1-11.4:1 CR lol. Thinking of going with a bore diameter of 4.040 as my 360 is 4.020 (fel-pro head gasket bore was the same 4.020) and maybe around a .040-.050 compressed thickness should drop my CR down into the mid to upper 10s.