You will need to find a 4 b serial number with a p7100 pump, than you can give that info to cummins to find the part number. I know zoom boom tellahandlers had a p7100 pump, also some bread trucks had them, you might do an ebay search for a 4 b with a p7100 pump and ask the seller for the serial number. good luck also try acd engines I bet Robin would know the part number they specialize in b series engines.