... I have a 10k Onan quiet diesel in the bus. I just have it sitting and hooked to fuel lines..... What to do? Seems to work fine?
I see no advantage to rewiring for 120, and several disadvantages. Do the best you can to balance the loads between legs instead. If you were to rewire for 120, you'd need to go to an 80-amp breaker, and upsize the feeders to accommodate it.
P.S. He did not think the gen could be wired st 120?
I think he's wrong, but I don't have the prints, either. You might have to open up the wiring box for the head, though, if the unit was not made at the factory to be easily convertible.
Can one still keep their 50 amp park plug and transfer switch? ...
Probably not, again because you have 50-amp transfer gear, and if you have, say, a 10 or 12k genny, you'd need to upsize everything to 80 or 100 amps.