dry timing chain

I have a problem with the oiling system on my sb 350. I installed new main and rod bearings and ended up with fairly tight clearance on both.
Anyway, the problem isn't there but with the cam bearings and the chain area. On the cam bearings the end bearings- #1 and #5 they look pretty good with both still silvery looking but the three in between look blackish with a little silver on the outer edges of the bearings.
In the chain area when I put it back together cleaned inside of cover of all greasy and grungy looking stuff to where it was shiny - chrome cover- and after a total of maybe 3-4 hours run time I decided that something wasn't right and tore motor back down it was still totally dry! Cam and crank and rod bearings seem to have gotten oil as they were wet but what would stop oil from getting to chain? Never had any bad knocking sound but just seemed to idle rough and generally didn't sound right. have tore down to point that all that is together is piston-rods are still in and heads are still on- everything else is out. Would it hurt anything to clean inside of block and oil passages
from this point? Thanks anyway- problem resolved.