More info on the problem...

Checked the alt. belts, and tightened them, checked the charging system, and got good results there - about 13.7 v at idle, and no less at 2500 rpm....

Changed the plugs, cap & rotor... wires looked fine - no "fireflies" at night, and no shocks when moving them around while the car was running...

Better running, but still have the "spark-knock" under load, and resultant overheating (not into the red zone, but needle climbs more than I'm comfortable with)

Tried to turn the distributor a bit to see if maybe the timing needed a bit of tweaking, but was unable to get it to move at all... Seized in the block, maybe? Loosened the clamp nut until it was nearly off, but still not able to turn the distributor... Anybody else ever see that sort of thing?

This one doesn't have any vacuum puck on the side of the distributor, so I'm not too sure how spark advance is accomplished, but I'm assuming there must be SOME mechanism for doing that.....?

Thanks again for your assistance and advice!

Joe