[DAVID GAGNARD]

Clois;

What size radiator and fans do you have as well as diameter of your crank and water pump pulleys?????

Here is my setup;19x26 aluminum Griffin two core radiator,20" puller electric fan from a Caddy or big Olds,not sure,and a 12" pusher in front. Crank pulley is 6.5 inches in diameter,water pump pulley is 5.75 inches in diameter.

I fought with heating problems for a year and did everything except call in a witchdoctor,also spent more money than I care to admit, all for the sake of driving in parades.

Here is what I found,small 19x19 oringinal Mustang radiator was marginal for street use and no good for parades,so I switched to a bigger radiator 19x26. That helped but she still ran hot,went thru 3 after market electric fans with poor results,I find they are not shrouded very well and most blade configuration is not the best. Got the Caddy electric fan free at a body shop. It had one to the four mounting "ears" broken off and they replaced it and were going to throw it out,so I took it and it has a very good shroud as well as blade shape and beats the a/m ones hands down,no contest. Did better in parades but still got hot. Put a high volume aluminum water pump with same results as before. Called their tech line and went thru whole scenario with tech guy and first thing he asked was pulley size. They recommend for street use pulleys of same diameter and THEY WERE RIGHT. Took off my crank underdrive pulley replacing it with stock pulley and have had no heating problems since. Idles in 100 degree heat parades for 45 minutes at 180 and after 45 minutes it slowly climbs to 190-195 and pretty much stays there.

The underdrive pulleys are designed for racing and not street use although they may advertise them for the street. With my underdrive pulley,once the car was warmed up,open the radiator cap,idling 800rpm and the water would just trickle out the flues,with the stock size pulley,it flows out an inch to two inches. Quite a big difference in flow.

I'll gladly give up the 5-10 hp of the underdrive pulleys for cool running and peace of mind for not having to worry about overheating........

David