Did you pull the covers and look for oil?
You may have already answered this but you are not re using the stock rocker bolts correct?
ur mechanic get a chance to look it over yet?
when you pull the covers, check for oil. If a cam bearing spun or something else and ou aren't getting oil, the lifter can't pump the oil it's not getting.
I would pull the heads and check the valves and pistons looks like your cam timing was off and shat hit the fan.
yeah I remember you saying that now, I would still pull the head, and check every thing out.