Help with pre ignition ping

I can only assume that you live near sea level(less then 1000 feet)

10.5:1 (I bet is more, or the cam is smaller) is just to much for pump gas at sea level.

When you pull the head off, REMOVE all Sharp edged in the combustion chamber and piston.........This could be part of the problem.............


Get a part time job, for all the racing fuel, and have some fun this summer :-D