New bearings should hold pressure better than that- - - - - -I'd suggest making sure they're the right size. If you've got standard-diameter bearings on a .010" undersize shaft, for instance, the pressure will drop radically as the engine warms up. Have you put any road miles on it yet? A mismatch on rod or main bearing sizes will produce some nasty knocks as soon as road load is into the mix.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!