I get the distinct impression that your engine builders don't know what the hell they're talking about! If I read your post correctly, they've completely shut off the oil flow to the rods, and mains in your engine! Did they install the correct "pointed" threaded plugs in the front, and the standard NPT plugs in the rear of the block? Did they plug the oil gallery's in the "tower" in the tappet chamber, if so - then they've probably "pre destroyed your engine"!! DO NOT RUN IT AGAIN until you / they resolve this issue! I bet they told you that they've built plenty of "record setting" Chebby's!
I'm watching you.