How much vacuum does the engine make during idling in neutral and in drive?
I have a fairly similar 360ci engine, powersteering, Doug's headers, only with a XE256 cam and 11.3:1cr.
My car has a fan shroud which really helps.
With the 160F thermostat it stays around 150F pretty much all the time, unless I get into heavier traffic, where it will climb to 160-170, 180 max. As soon I as hit open road it drops back to 150-160F.
What's the diameter size of the crank and waterpump pully? Can you locate and try a smaller waterpump pully perhaps?
I know the waterpump pully on my setup is roughly 14-15cm in diameter.
