There is a "tool" to space the starter. It is a 1/8" rod. You slide it in between the flywheel & bendix shaft. They used to come in starters and shim kits. Loosen the inner bolt and remove the outer one to slide the shims between the starter & block. Adjust until the rod slides into the gap with a little resistance, but do not force it, add a shim they come in assorted sizes. Instructions are also on the package. The last one I bought was about $3.
Brad
