Is there a lot of blowby? If not I don't think a leak down test will tell you anything. Those compression readings can't be right. I don't know of any engines that will even fire at 40-70 psi. It would have to sound like its just spinning with the plugs out. Too consistent for there to be any single cylinder issue, which means there has to be something common among all cylinders. Camshaft installed wrong is most likely suspect. Or all of the pistons are way below deck.