All,
In my attempt to determine the cause of a hot-running TIICo transplant, I find the cooling system in fine shape except for 2 things: 

The fan switch isn't turning the fan on when it should - there is no "low" speed.
There was no thermostat installed.

I replaced the switch.  I put in a 80 degree thermostat.  I don't have a good test on it yet.  

Would a missing thermostat cause the engine to run hotter than it should?   I'm think that maybe the coolant is passing through the radiator too fast, and not giving up enough heat as it zips through there.  Am I off in left field?

I will see how these two items (hopefully) improve the cooling situation.  I will then put in a quart of super-duper water wetter.  I will see how that works.  Lastly, I'm going to add an external oil cooler.

Bob 
East Haddam, CT