looks like my baby doesn't have much of a peer group! i can understand if they're all as rusted as this one - sane people just don't bother with such machines.
next guesstimate is to measure the space and bolt patterns where the original radiator was, and see how far off the 'little' truck one is.
if the assembly manual says the 3000 radiator is diff from the 4000-6000, surely someone has some documentation as to HOW they're different? i figure worst case, i can make the pickup type radiator fit, it just might not be too pretty