I would want 80-85 if you have FE rod journals and spin it more than 6000 rpm. The large diameter and narrow width will live better with more pressure if you spin it up.Otherwise, 65 psi max HOT is a good number. Bearing clearances and lifter bore clearance can effect idle pressure. I also think very loose rocker clearance in a top oiler system can make the #2 and #4 mains and the #2/5 and #4/7 rods experience lower pressure, but you'd never see that on a guage reading off the filter bracket. Lifter slop can be a huge bleed on the system, and often is the cause of low idle pressure when all else is set up just fine.