The Bus Depot catalog lists three oil sending units for Vanagons.
How do I determine which two of these are used for my 87 GL?
They are listed as follows:

 83-91 .3 Bar    Side of Case   Pt. # 056 919 081 C
 86-91  .9 Bar   Rear of Case   Pt # 068 919 081 A
 86-91  1.8 Bar  As Above?       Pt# 056 919 081 E

Thanks in advance for any guidance on this.

Mark Smith