my truck is a 1.5 ton I believe it is a 1941 or close to it, the engine number now is BDR 15592, I'm not 100% sure if the motor has ever been changed but I see on the original ownership papers that came with the truck it has another number BFR 246846, this number has been crossed out, not sure if this was a mistake originally or if this may have been the original motor?