63 Dart overheating issue

Update:

Picked up the radiator from the shop today. Couldn't believe it was actually CHEAPER than the quote...by almost half. Gotta love when that happens. Anyway, put it back in with new cap and thermostat and fresh coolant and took it out for a drive.

HUGE difference. Had it out for 40 minutes and it never even got to the lower line of the operating range. Even the hot start has improved (not gone but much better. makes sense that the engine is cooler, so is the fuel).

Think I'm going to bump the timing back up a little to 5 BTDC as it doesn't seem to like the 2.5 BTDC. I doesn't start as nice and it's boggy, along with not as good of an idle, even after adjusting the carb. Ran great at 7.5 BTDC so I will try 5 and see how it goes, now that I know the root cause of my issues.