First- - - -RIGHT AWAY- - - -check out the oil pressure! Put a direct-reading gauge on the engine, and leave it there through the warm-up period and normal driving. Any other work is secondary to keeping the bearings lubed.

You might also want to put something like a candy thermometer in the top of the radiator while the engine warms up, and see where the temperature goes when the thermostat opens.

A sticky thermostat will allow the engine heat to go up without the radiator overheating, at least for a short time. Check to see if the block and/or head is noticeably hotter than the radiator. A good flush and a new thermostat might be a good starting place, after you've checked oil pressure, of course.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!