[jeepguy1948]

I will do some checking. I want to point out that I wasn’t proposing anything more drastic then additional head gaskets. The heads are off the motor now but when it was run last week I was having pre ignition/knock/ping even with the timing set 24 degrees total advance. This is not my motor, it belongs to a friend and I don’t know for certain how it’s going to be driven after it leaves my shop. I can lift the pedal a bit if it starts knocking but I can’t count on all the grandkids etc that are going to drive this (‘51 F-1). It has to be dumbed down a bit. Pistons are very clearly marked .100