Need gz250 motor or top end parts

[kevin]

I have a 2003 Gz 250 that was allowed to run low on oil by a previous owner. The motor failed by dropping a exhaust valve into the cylinder. The cylinder head ,piston ,cam, and rocker arms are all toast. I can replace the top end ,but am a little afraid of any transmission damage. There was scant oil left in the case when I drained it ,but no noticeable metal. I am hopping to find a good engine on a salvage bike or top end parts at a reasonable price.

Thanks, Kevin