Change in plans. Another new build begins
Correct me where I'm wrong. The line coming up from the oil filter adapter to the back then thru the back of the block is feeding the rocker arms and the front of the block.
It looks like there is a connection for feeding the rockers at the center of the lifter valley. Making it full time oiling to the rocker arms. So I would think that the cam bearings on #2 and #4 are blocked causing the grove in the cam journal to be inactive.
Is the passage at the driver side of the #1 main blocked?
Very interesting dual pickup setup. Really neat short block.