I'm using mid-nineties F*** E350 16" rims on my 49 3600. I don't have more specifics, I did that a few years ago but that's what the shop I got em from said they were taken off of.
I spaced the front rims out 1/4" although they did clear without; that was more of a caution as the rubber was close to the tie rod. No problems, have a few thousand miles (miles not KM) on it now.
I've got beauty rims on it and have been investigating dog dish hub caps using the clips ya rivet on. The bigger challenge I see is the rear - now on one of our fire trucks, we have a cool chrome center cap that goes over the full floater. I'd love to source something like that. I'll grab a picture next time I get a call out (just a voluntold).
