R4673, a '63 R2, ran hot from the day I got it. I tried everything. New 
radiator cores, cleaning out the block, 6-bladed fan, 180/170/160 degree 
thermostats, drilling bypass holes in the edges of the thermostats - all 
the recommended fixes. Red Line water wetter helped a little, but the 
thing that totally fixed my overheating problem was replacing the viscous 
drive on the fan, which I had thought was working perfectly. I now run at 
whatever the thermostat temperature is. I had to replace my 180 degree 
thermostat to get back UP to a normal operating temp! Make sure you get 
the newer of the two available units.
Abbot Moffat" <abbotm@microsoft.com> 01/16/02 07:02 PM