I got just my new to me 1987 Sami home. It starts and runs good but temp shoots up to the red in a few minutes. Not sure the engine is really as hot as the gauge says it is but so far have replaced the thermostat, rad cap and radiator. Even took the new thermostat out and am running it without one - still very hot. What do you think - sending unit, receiving unit, head gasket, timing?? No oil in rad, no antifreeze in oil, no white exhaust. Need help.

Gerry