If a distributor housing isn't installed, the lifter oil gallery down one side won't receive any pressure. No oil to the rocker arms on that cylinder bank is the result. I use a junk distributor with the teeth ground off the gear as a priming tool to prevent that problem.
Jerry
I'v got an old distributor (87 - '95 TBI) w/ the gear removed, stick it in the hole & spin it with a drill. Doesn't hurt to rotate the engine some to get oil to all the rod bearings.
