Who assembled the motor? Without going to the shop and looking at manuals and a bare block, I could not help much. No oil to the sending unit is not good. I always wash my motors out real good before I assemble them and use a brush to clean all oil galleys. That way I can check for blockage. I squirt water in every hole. You either have a plug gone or its blocked. If you do not have oil to one side of the head, then it is most likely the cam bearing is installed with the hole not lined up. That is the very first thing I check before I even wash a block. I run a long drill bit down the hole to make sure. Sounds like that may be your problem there.
One thing I do is remove all of the plugs myself before the shop gets them. I do not give them the plugs to install them. That's my job. If they forget, then some crap could still be in them.