V6 Radiator v I6 Radiator

[Andice]

The '64 1/2 ton Fenderside that I am restoring left the factory with a 305E V6. Somewhere along that way it was refitted with a 230 I6. One piece of literature that I have at work indicates a larger square inch cooling area for the V6 radiator vs the I6 radiator. There is also a smaller fuel tank in the one truck vs the other but I am away from the literature and can't recall which engine option included the larger tank. Can anybody tell me if there is a quick way to tell the difference between the two fuel tanks? How about the radiator cu in measurements?

In time I would like to go back to a 305 so I'd like to get my ducks in a row beforehand..... like the radiator, rear end, drive shaft, motor mounts, etc.