what other motors will fit in an 83 250R

[Dman450R]

I've got an 83 250r rolling chassis with a worthless engine. I'd like to find a different motor to put in it, and I'd like the swap to be as easy as possible and with the least amount of modifications necessary. I've searched the forums for info on this, but can't seem to find any. I don't care if it's faster or slower, I'm just basically looking for an easy swap to get this thing moving under it's own power. Any ideas?

[RodKnockRacing]

CR480 is the only thing i know of you just have to get a motor mount kit

[TheRealFatShady]

Yep, CR480 or another 250R engine. I have a spare one with two heads/cylinders, just need a piston set.