2002 Polaris Edge 800 melted exhaust valve rod

I have a 2002 Polaris Edge 800 that had the dreaded exhaust valve melt down. It caused a catastrophic piston failure with surprisingly no damage to the cylinder or the head. I have the piston and gaskets on order but am having a hard time finding the correct part number for the new stainless exhaust valve so the problem doesn't happen again.

Can anyone help me out?

2002 Polaris Edge 800 melted exhaust valve rod