If you have a 2002 with a serial number below 2300046825 then you need to go with 21134777 pump and the new pipe 840001.
If you have a 2002 with a serial number above 2300046825 or if you have a 2002B or a 2002D then you need the 859428 pump.
In either case you should order the little O-rings and the gaskets to go along with pump.
Hope this helps.
J. D. Neeson