Cuda Dilemma

Son has been wanting to turn it back into a street car for over a year. Last year he pulled the engine out to freshen it up.. I'm not up there to help him anymore, so I made arrangements for him to take it to the old guy that I used to do all my machine work, who is now retired and just works out of a small shop on his property now. He also assembled the engine this time for my son. Had new adjuster screws put on the rockers. The hydraulic .509 cam looked like new he said. Put new lifters in(?) . Any way son put engine in car( about a year ago) and got it running and said it ran like crap. I talked to engine builder, he said to bring the car over and he would check it out, but son never did. He kept messing with the timing and valves.. Says there isn't an hours run time on the engine. Pulled the valve covers off the other day and all were loose again. Told him to pull the adjustable rockers off and put his stockers back on to see how that looks , he pulled #7 exhaust lifter out and it was all ground up . I don't know if he should have did a cam break in for the new lifters or what, .