Thats pretty high comp are u running a race fuel or premium fuel in it. Poor quality or low octane fuel could cause that maybe. Usually pinging is caused by 2 much advance but surely 10 deg would be fine unless ur dizzy is advancing heaps but that would be a constant problem in revs not just when hot. I would try hotter plugs. I dont have a part number but i have some that would handle what u need. i can check part numbers tomorrow if needed.