Erratic Timing

Wow so much awesome info! Thanks! Like an idiot I dropped one of the carb sight plugs while checking the fuel level....Can't find it anywhere. Anyway as soon as I can get another (I might be able to borrow one) I'll fire it up, try 8*, and note where the timing curve actually is now. I don't think it's advancing between 600 and 750, but I'll definitely have to double check.

I did take if on a quick drive after I set the initial at 10, and it was pinging under load, so I'll have to adjust something.
Thanks for the help! I'll keep y'all posted.