1. I think (but my wife says not very good) that fuel pumps on a 52 Chevy truck and my '52 GMC truck will interchange. Anyone have an opinion?

2. I recently came across two fuel pumps among a bunch of GMC 228 parts. One has a rebuilder's tag "531" and no other markings. An online picture of an Airtex 531 looks very similar. The other is a Carter MO-735. I'm too lazy (it is 102.4 degrees outside right now and my garage does not have A/C) to pull the pump off of my truck to see if either will fit. Both have seen better days. I'm considering having one rebuilt for use as a spare.
2a. Who would you send the pump to?
2b. Which pump would you send?


'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.