Exhaust valves that can take the heat

I have two sets of Del West Ti waiting for a home.

They are used SB2 NASCAR units Ill have cut down to fit my next project... likely a Gen 3 dirt track project. 2.08/6mm intakes and 1.66/7mm exhaust. They need to be cut down and have the stems shortened and regrooved.

IIRC I paid $75.00 per set of 8.