Chip, yes, you will have a small amount of metal dust at the first change unless you chamfered all the edges on the rod, cam & main bearings before assembly. As for oil pressure, my 54 235 has 15-20 psi hot idle at 450 rpm, about 38 psi at speed. In experimenting, my friend & I have found huge differences in pressure and flow with new oil pumps. The quality control is horrible. We even went so far as to shim the relief valves. With the same amount of shims, my pump maxed out at 45 psi, my friend's pump pegged his guage at 80 psi.
