If you can reduce friction with conventional motor oil, or synthetic, or either one with an additive, you will reduce engine temps. Tight tolerances also increase engine temps. Incorrect timing, carb jetting and poor cooling system efficiency can also increase temperatures.

Say your motor is 100% efficient in the tolerance, timing, cooling and jetting area and your car runs 180 degrees in 100 degree temps. After 10 years of running the car and not thoroughly overhauling EVERYTHING, you will lose efficiency percentages in every category. Say you lose 20% across the board which increases temps by 36-40 degrees. Motor now runs at 215-220 degrees.

However...

If you build the motor correctly and have correct tolerances and have thoroughly checked the motor over well, there should be no reason to specifically use brand X to reduce oil temps. If that is the case, buy an oil cooler with a fan.

Attempting to cure an overheating engine can only be accomplished by properly building and tuning the aspects of the motor that will promote overheating. You get to the root of the problem and you will cure your overheating without resorting in spending $200 in additives.

If it bothers you that much, have the carb rebuilt and distributor recurved, then see what your car is running. (I say this assuming you have tried changing T-stats timing and jetting already).

If you do not want to work on the timing and carb, I suggest buying an oil cooler and fan and removing trans lines from radiator and buying a trans cooler. I do not recommend buying more parts to correct a problem, rather correct the problem(s) that is causing the issue. If you do not address the root of the problem and continue to band aid, you will really be in trouble.

Trans cooler alone with a 4 core will reduce temps by 10-15 degrees.

Oil cooler/fan and trans cooler can decrease temps by 30 degrees.

Again, I do not approve of band aid methodology and do not promote quick fixes, but if so, need be.