All the e36s use the same replace pump, the unit itself, not their housings and such. The differences are whether theyre the passenger side with pump and sending unit, the drivers sending unit, and the other variable of whether they have one or two lines that go between the tank sides. They all pump the same volume of fluid prior to the FPR which changes the pressure for the rail. For OBDI engines, its regulated at the rail, the OBDII FPR is underneath the drivers side floor and is changed to the required psi before it even reaches the fuel lines to go to the rail.
The only other possible discrepancy for parts numbers would be the strainer. The actual size of the pumps are the exact same as well as their guts, all OE VDO, thus, no volume increase nor decrease.
Here are the direct replacement pumps for the e36.
Bosch
http://www.rockauto.com/catalog/moreinfo.php?pk=976817 Delphi
http://www.rockauto.com/catalog/moreinfo.php?pk=1114515 Beck/Arnley
http://www.rockauto.com/catalog/moreinfo.php?pk=1997944 Airtex With OEM VDO pump
http://www.rockauto.com/catalog/moreinfo.php?pk=59972 Youll also notice that the bosch unit is a replacement for 93-2005, m42-S52-M54.