410 Compression Test and tuning.

That's good to get a handle on a baseline.

Don't know which distributor, but it sounds like you have the total number figured out. Get the initial correct and make any adjustments. You will get it squared away.

Does it have a thermostat or restrictor washer in the upper radiator line. Could be the water is moving too quickly. The overheating could be timing related depending on RPM.

Nice Duster!