Re: 302 overheating
What's it in, electric fan? Serpentine belt conversion? Could be something as simple as the wrong radiator cap or the spring in the old one is worn out. It'd also help to know the actual temp, I'm assuming that 3/4 is the temp gauge. If you stepped up the heat range on the stat, it might be something as simple as the cap, but I'd expect the problem more on around town driving since there's less air flowing through the radiator than on the open road.
Chewing on asphalt and drinking dinosaur wine