Hi there I also have a 39 GMC truck it has a block casting # of 3835766 it is forward of the fuel pump. I can not find that any where on the net. My vin says it is a TT13226 engine, but I can not see a number on my engine behind the distributor . Also my vin is 9943500505 first 9 means 1939, next two 94 means 1 ton 35 means panel and 00505 is the # of the truck in 1939. Did you ever find out any more info on yours? Please let me know
