[WE7X]

Since it is a bus, is it a rear engine or front ?
I have a 1970 RM-7500 which is a rear motor (401M) school bus chassis, converted to an RV.
I had to replace a Water Pump many yeas ago, while on a trip east, and had some trouble finding the correct one. I had the old pump with me, so at least I had something to compare.
There were three options as I recall, and they all had to do with the length of the impeller shaft. All had the same bolt pattern, but I think the flange for the pulley was extended a bit on the one I needed.
I have the air brake pump setup on mine, and that may be the difference, even though the air pump belt does not run across the water pump pulley.
I have looked, but do ot see any record of a part number for that replacement pump i purchased.

Rod Johnson
Issaquah, WA