So what's the deal? Which carb is the right one?

Back then many trucks and Vans had more lenient emissions specs than cars
Thanks for the reply, Don. Here's where I'm at. In the first photo below, there is a filled in hole that looks like a dimple between the two screw holes on the left side of the carb. On my Holley 1945, there is a metal nipple in this spot, with a rubber vacuum hose attached to the nipple which supplies vacuum to the heated air snorkel door. But since this nipple doesn't exist on the 902 carb, where am I supposed to plug in the vacuum supply for the air door? On the right side of the carb (second photo) the lowermost of the three holes is where the charcoal canister line plugs in. But this carb has no nipple there. So would I somehow have to extract the nipple from my existing Holley 1945 carb and insert (screw? push?) this nipple into the new carb so that I could have the charcoal canister correctly hooked up?

IMG_4748.jpg

IMG_4749.jpg