Help with pre ignition ping

thanks guys, to answer a couple things the 32 advance is with the vacuum disconnected and plugged off. The car doesnt ping nearly as bad with the timing at like 25 degrees advance @ 2800 but the ping never fully went away.I beleive the cam is some where in the 545 lift/ 240 dur but I cant be too much more specific at this point I'll see if hes got something more specific on that.I am going to get a new compression tester soon, he just figured he'd try the av gas as a quick experiment. thanks again