These head screws are 1 1/2" long. Actual length 1.465-1.490"

The very first run of 500 engines in 1983 used 1 7/16" long bolts, Actual length 1.415-1.430". If your engine does not use an o-ring to seal the head these are the correct screws.

We do not have the shorter screws but you can grind these a little shorter and it's possible you may bot have to grind them at all.