Not too much information on the timing your running, or what type of dist/ignition, or the method of advance...same with the carb?, a lean condition can cause unnecessary heat? what are you doing to determine a lean/rich condition?.....seat of the pants feel is not a good lean/rich indicator, plug readings?, O2 readings?...



As far as the mechanical end, IMHO I'd toss the clutch fan, run a factory 7 blade HD fixed fan, the space between the fan to radiator is not as important as how much blade area is inside the shroud, you should have at least 50%-75% of the fan buried inside the shroud for a proper pull, play around with different spacers to achieve the proper spacing, make sure you try and maintain at least 1" or more away from the radiator, as fixed fan blades at high RPMs can "flex" outward towards the radiator...

As far as the Chemical end, I'd recommend ZEREX G-05 Antifreeze, distilled water 50/50 mix, and 8-10 oz. of REDLINE water wetter