[Old Tin Indian]

I also have a Hayden 2797 Clutch Fan. It works like a charm. The 2 biggest changes I've seen that made a definite difference in cooling on this car was setting the impeller to plate clearance and getting rid of the old, huge trans cooler and installing the more efficient plate cooler. It heats up at a long light but cools right down when more air from moving goes through the radiator. I'll live with it. I don't drive it that much.
Tony

[AdamIsAdam]

http://transamcountry.com/community/...?topic=56642.0

Some good fan testing here

[Old Tin Indian]

Thanks Adam. That was definitely a good read. I do have a high flow 160* thermostat in it. I also drilled a couple of 3/16" holes in it. I also have a '66 GTO water pump pulley on it to speed up water flow. I've been pondering looking for a slightly smaller pulley to speed things up just a little more. I'll eventually narrow the problem down a little more. I just wish the Pontiac Engineers were a little more diligent with our cooling systems.
Thanks again.
Tony
by the way the '64 looks really cool.

[AdamIsAdam]

Thanks. At least it "looks" cool if not always running that way LOL

Is there a list of water pump pulleys and sizes? Nothing on my car is stock, so I don't know what size I have and what size may be best.

[Old Tin Indian]

not that i know of. the original pulley on my '67 gto was i believe 8" in diameter. the one i have on there now is off of a '66 gto and is 1" in diameter smaller. eventually i'm going to look for a smaller one.

[AdamIsAdam]

My water pump pulley is 6" and crank pulley is about 8"