350 runs hot...need help
 

I just put in a new 4-core radiator and a higher flow thermostat in my truck. Idleing it hovers just below 230. If I punch the gas the temp drops. If I hold it at a constant RPM it heats up again. I havent driven it anywhere while it is hot like this. I have even put a furnace blower infront of the grill to blow more air. The shrould is on and the fan is moving a good amount of air. I have been running without a thermostat because I just figured I needed a bigger radiator. I have a year old Remanufactured water pump and new hoses. The motor is a '76 350, .060 over, Vortec heads, Elelbrock Performer Intake, and Comp Cams 252 High Energy camshaft.

The engine has done this since I put it in in early July, but I just took the thermostat out. I had a leaking head gasket problem earlier, but I seem to have gotten that fixed. Other than the temp, the engine is working good.

A mechanic friend said to check and make sure I dont have the Intake gaskets on backwards.

Thanks for any help,
Mike

Removing the stat will only make it worse. Try installing a 160 degree stat on it.
Normally idleing with high temp means lack of air, and high speed over heating would be lack of coolant flow.
Do you have an A/C truck? If so, are your finns bent? Are they blocked? Did you look inbetween the condensor and the rad? Is your belt slipping? Do you have a worn fan clutch?

The more you bore your cylinder walls on your block , the more heat it will create. Boring a 350 .60 over might be giving you all your problems .