I used stainless exhaust valves (stock size) from Vintage Power Wagons, as an added measure of saftey with unleaded gas. The block should have hardened valve seats from the factory, so nothing to worry about there.
I'd also recommend Earl Edgerton of Edgy cams for your cam grind, he can be contacted from his website:
http://www.visionquestwebdesign.com/edgycams/ Pete
