picked up some heads, and wondered if they are worth using

[sduckworth13]

I picked up these heads from a guy that races circle track here in Missouri. The are 3951598 Chevy 400 sbc heads. I know thay have stainless steel valves in them, beyond that I don't much about them. Can anyone tell the valve size. Casting number shows they have 1.94 exhaust valves and 1.5 intake valves. But the valves look alot larger than the valves on my 333882 heads which are 1.94/1.5 also. Can anyone help me out. Thank you