I went and got my new project last weekend. I'm not real keen on buying cars on eBay, especially old ones, but I broke my own rule and bought a '50 Dodge b2b truck. I am not disappointed with my purchase, especially for the price. It is pretty dang solid for a 64 year old truck. I have always wanted a stock old pickup. My '05 with a 4.7 & 6 sp pulled it just fine, it was an 8 hour round trip.
I read that they used them until the late 70's in industrial equipment. I think some of the millitary trucks used them for quite a while, too. They sound pretty solid, with drop in bearings and a pressurized oiling system, compared to some other early engines, but we will see. It has made it 64 years with the flat head, so who am I to change it now?