I have just discoverd that one of the BD's I brought is an early 4speed model with the serial number 2D286 and when I looked this up it is betwween 1939-41 but it gives three different versions of the DJX engine, mine has no engine serial number plate so how can I tell which it has my Oliver BD has a DJXC and the plug to view the timing mark is on the oposite side of the engine the one in question has it under the starter motor and also does not have the same adjustment on the fuel pump coupler for the timing. Could it be a DJXB or is it just an early version of the DJXC. Still need a pump if anyone can help!!!! Sam