scrambler 250 restore project

[Aregistereduser]

Hey forum just bought a scrambler 3 wheeler and i need a engine for it, can someone tell me a few models engines thatd fit in there or somewhere where i can get a scrambler engine? Thanks!
ill upload a photo up when i get home on my phone right now, it came with a gas tank, fenders, seat, tranny, whole frame, and working front breaks.

[Blown 331]

Awesome. I can't wait to see some pics. I just picked up my second running Scrambler a few days ago. I'm not expert on what engines swap but I would think any other 250cc Polaris, hopefully someone else who knows for sure can chime in.