Fan clutch or not

[thunderbolt]

I have heard alot of stories over the years of rebuilt 289's running hot in older mustangs. Don't know why, my stock one ran around the T on the temp guage all the time. Anyway, I would get a total cooling system overhaul beginning with the radiatior. Have it cleaned out, rodded out if need be. Change your thermostat to a new one and get a new radiator cap. If the radiator is bad, replace it with at least a 3 row unit. Aluminum is expensive but has much better heat radiating qualities, and is lighter. If you replace the water pump, go with an aluminum unit. If you are still warm, think about the water wetter. If your cooling system is up the snuff, you may have an engine problem, probably insufficient cleaning at the rebuild. This last problem is probably not it but keep it in mind if all else seems to fail.