Mechanical vs hydraulic valvetrain

If you have the adjustable rockers, then they have not been swapped for the hydraulic assembly. Hydraulic slant rockers are non adjustable and do not have the hex nuts. They also take ball and ball pushrods, rather than ball and cup like you must have. ARE YOU SURE it is a solid camshaft and has not been changed to a hydraulic? You cannot "just throw" a hydraulic camshaft in a slant without all the other needed parts, because they do not oil from the lifters. They oil from the head, into the rocker shaft through the rocker arms and finally into the lifters, I believe. I don't think any slant six was ever drilled for an oil through lifter galley that I know of. They oil from "the other side". So, that means if someone just threw a hydraulic camshaft in it, it has likely burned up some "stuff".