I have a photocopy of an article in the MAFCA Restorer by Ed Rossig, titled "Analysis: Model A Fan and Water Pump". I wrote "11-4" on the copy, which I think meant the July-August 1966 issue (I made these copies about 30 years ago). In it he presents some charts listing "temperature measurements at various engine locations" taken after running different fans. Temps are remarkably close. #1 is usually coolest, and #2 runs close to #3 and #4.
The May-June 1978 Restorer had an article by Paul Moller subtitled "Nothing ever happens on no. 1 cylinder". In it he described a modification consisting of a copper tube from the water inlet to the back of the block. I did this when I installed the stock head on my rebuilt engine in about 1987 before I put the body back on the chassis. But I when I went to put on a high-compression head, I found that the fittings interfere with removal of the throttle control assembly. I had to raise the front of the body to get the throttle assembly off. I left the bypass tube off and plugged the block when I put it back together.
Joe
RossigCooling.jpg
MollerCooling.jpg