[P.S.]

What good timing (pun). After a discussion at the club meeting a couple nights ago, I spoke to Joe at Turlock Machine this morning about this very same topic.

Joe says that even with a Snyder 5.5 head, if your Model A motor is pinging with full advance, then you have the timing set wrong. Joe says that even after setting the timing the Henry way, it's prudent to check using a timing light with a timing mark on the motor to be sure that full advance does not exceed 26 degrees. Beyond 26 degrees, pre-detonation can occur and it will damage the lower end of the motor.

Joe went on to explain that even at (let's say) 25 degrees of advance, you will not harm the motor in any way as it was designed to run that way and even aircraft motors run full advance all the time after starting. That guy knows his stuff, and I believe his information to be gospel.

Joe is installing a 5.5 head on the long block he is building for me. He says it will run much better with the 5.5 head over a stock head or a 6.0 head.