I have a 1600x flow, What size valves should it have in the head as standard as the guy i bought it off said it had a vulcan head on?

I have just measured the valves and it looks like it has a stage 2 head like the guy said, Engine looks like it has been rebuil recently, It is currently running a single weber dcoe carb on a lynx manifold, What bhp should i be especting?