Atta Cruising speed that produces 2400 to 2800rpm, the ignition timing will want to be in the window of 46 to 56 degrees.
The trans should have it's own cooler.
Good luck with the electric fans. make sure they are rotating in the right direction.
BTW
the thermostat sets the minimum temperature; if you take it out for testing purposes, swap in a restrictor washer or a gutted old stat, to prevent erroneous temperature readings.
While in park and idling;
the rad needs to drop the temperature about 25/30*F from tank to tank. If she can't do it with the fans running top speed and the stat removed for testing, IMA suspecting the fans, or the fan-system.
Don't forget that water expands with increasing temperature. If the cooling system is NOT of the recirculating kind, and the rad is overfilled when cold, it WILL puke coolant until it finds it's natural level. After it is finished puking and has cooled off, pop the cap and witness the correct level. In my experience this will be above the cores and not much more than 1 inch below the top of the tank.
and
if the car still has a heater, you can set the blowerfan on high and in an emergency, extract quite a bit of heat this way.
and
Until you get this figured out, the water pump should be turning faster than the crank, which means the pump-pulley needs to be smaller than the crank.
EDIT
oh I see you know about liquid-expansion with heat.
BTW-2
The point in the cranks rotation at which optimum energy transfer of the expanding gasses should occur is in the window of 25>28 degrees AFTER TDC. All your timing systems are or should be, engineered to try and hit that mark as often as possible, under as many different rpm and load settings as is possible. Therefore;
1) if your timing is locked out at some racing number, that will be part of your problem, as retarded timing puts additional heat into the coolant,and
2) it is as good as impossible to give the engine the large amount of Idle-timing that it actually wants, with a distributor, and still be able to drive that engine at low rpm, without getting into detonation..... but that is somewhat combination dependent.
