OK guys, time to show my ignorance again.
I have this really nice pair of SII aluminum heads (bare). I would like to start looking for some valves. What's the best way to measure the seats so I know what size to ask for??
Also, what stem length and size would they take?

I have this really nice pair of SII aluminum heads (bare). I would like to start looking for some valves. What's the best way to measure the seats so I know what size to ask for??
Also, what stem length and size would they take?