Mike,
Thanks for the reply. I tried all four numbers and can't seem to find a replacement , or any of those numbers to come up. Might have to go to the parts store and see if they have a old cross-reference book. The innerweb and GMC Big Bolts don't play well.
The air pump was a vintage Midland, and used for air. The tank was plumbed into the hydro-vac line going from the intake to the hydro. I cleaned that up, but am looking for the correct check-valve and where it mounts, etc..
Thanks for the numbers, maybe I will strike gold at the parts store. I'm sure they will ask if it has air conditioning and power windows, but I'll work through that, LOL..
BaconFarms