Any pinging is bad..even if its just a split second, the slight knock is hammering your rod bearings, then imagine in 50,000ks you have to rebuild again. I would find that load cell with the knock and knock a couple of degrees of timing out.
The GTR buckets dont fit and its not viable to stuff about with them to make them work, if you want solids use the Tomei kit with springs and cams to match.
160psi of oil pressure is WAY too high, Id bet there is something blocking an oil gallery which is also causing your lifter noise.