ISO engine rebuild or new engine rzr 800

Ran my 08 rzr 800 outta oil on a ride an now im either needing a new motor or a complete rebuild kit top and bottom end. My motors still running its just smoking like a freight train and when you go ta rev it up you can hear a slight noise in the bottom end. Jus wondering if anyone on here has something laying around that they dont want n arm an leg for. If i do rebuild im wanting to go ahead and do a big bore kit ta get alittle more power.