Technical running hot 210 degrees mild weather

Checking the timing/tune first could save you a lot of time and expense

 

We will be watching.

 

Running down the freeway you don't even need a fan, if anything the fan is creating unnessasary turbulence. The radiator is the bit doing all the work so get it right before throwing other stuff at it.
The other thing to consider is the size of the pulley on the water pump. At 70 m.p.h. It's spinning it's freckle out and cavitation the coolant.

 

Ok so the damper has moved on the crankshaft. Timing is off.
vac***n advance was stuck.
Starting the timing thing all over. Guessing the heating and bad gas mileage problems will be solved.

 

I'm thinking I'm agreeing with you.
You are on the right track now.

 

I got it apart. Will finish tomorrow and check timing.

 

The correct temperature for a SBC, for complete combustion is 205F.

210F is just fine, and is within the accuracy range of most gauges.

If you insist on running under 200F, you will lose both power and mileage.

Modern fuels make reading plugs a near useless exercise. If anything, your plugs being light brown is a clear indicator that this engine is running just fine the way that it is.

 

My experience is, low speed no problem, high speed, radiator plugged. Coolant flow low.

 

Then add: Timing retarded, incorrect ignition advance, lean fuel mixture, poor air flow through the radiator, air flow blocked by fan/shroud, air restricted from exiting from under the hood, slipping transmission/clutch.