How do I stop the detonation

tiger wrote:The engine is a 460 bored .060 over, flat top lightweight speedpro forged pistons, eagle rods, balanced, c8ve heads home ported using scotty's web site, 2.20 and 1.76 manley stainless valves, cam research solid lifter cam 530 lift on both with 222 and 224 dur. at .050 with 110 ls this cam is so small because of the vaccum rule in our class, 1.7 crane rockers, guide plates, 3/8 pushrods, scj intake and exhaust manifolds, 2 1/2" exhaust pipe into a 3 1/2 Y pipe, prosystems 1000 holley carb, it is not zero decked the pistons are about 20 in the hole.

I have turned the timing down until it quite pinging but it runs like crap at 18 degrees. The distributor weights are welded out since it is race only. I tried a distributor with light springs in it that advanced out at 2400 rpms, but it still pings. He is using the hot plug right now. He is using 91 octane pump gas and the rule states no race fuel.  We put a can of the torco additive in it and now it does not ping until 32 degrees of timing anything over that and it will ping.  He is going to add the other bottle of additive and see if that helps.  We are going to try some 100LL in it also.  It only has detonation at the initial hit of the throttle, at 34 degrees of timing the detonation is their at just the initial hit of throttle.

The owner was thinking of buying the MLS head gaskets that are .023 thick and getting the quench back to where it should be.  I think that will be cheaper, but will it still ping once it gets the quench back to what it should be?  The thinner head gasket will make it act like it is zero decked correct, but will that make it ping still with 91 octane?