[The world block I had came with a small machined undercut at the top of the lifter bores. It leaked top side at full lift .420 lobe lift. Leaking so bad at top didn't check bottom of bores. I found it prelubing could not build pressure and pulled the valley cover..I wish I had took pictures. Sold the morels to a member on here. May have just been a fluke deal with my block. Purchased it new from indy back in 08. Mock yours up and prelube it before you put it in just to make sure. I was curious if anyone else ran into it.