<VV> Oil pressure problems

[Cliff Tibbitts]

So close and yet so far.  While pre-lubing the engine prior to my initial
startup, the drill suddenly began to load up, and I noticed the oil pressure
jumped to 75 psi.  Obviously there is a restriction someplace, any ideas?

Stats:  the engine was completely rebuilt.  All oil passages were cleaned
out as best I could.  I am using the original pump gears.  I did not replace
the check valve or either of the by-pass valves in the oil adapter.  This is
where I suspect the problem lies.  I am using a stock oil filter.  The only
thing about this engine that varies from stock, is the Clark's adapt-a-bolt
where I have connected the electronic oil pressure gauge. 

Any suggestions appreciated, 

Cliff Tibbitts
Lexington, KY