Camshaft timing makes a big difference when checking compression. If the cam has a lot of valve overlap, then some of the compression goes out the exhaust before the intake gets closed all the way.
Once you get the engine broke in good, recheck the compression if you are concerned about.
I would really caution you about checking a new engine before the cam has been broke in, its a really good way to wipe out a cam! Read up on oils and break in procedures.
Joe
