I am going to ask the basic "are you an idiot" questions

did you do the head bolts in the right order, with new head bolts?
did you put in a head gasket? was it correct? no sealer/coating on it?
Have you run the engine at all?

you have a even reading across the board, so its not likely is a damaged valve, but you replaced the valves correct? did you lap them in or did you just stick them in there?

have you tried starting it? does it run? try another gauge, maybe it just reads low?