OK, time for an update:
I replaced the 318 with a 302 LS1 big block Poly engine and now I'm hauling Caterpillars through Ukraine.
No.
I was wrenching all that last night to have it running for that one day at the track. Weather was cold with showers. I made one pass on cold slippery asphalt and I went 8.2 with pretty much wheel spin. Then the crew stopped me on the return because I was leaking oil. It had a high volume pump in it and I noticed the gauge showed 110 psi at idle and hot. It went beyond the scale as soon as I hit the gas pedal. Oil was pouring out from the 90° adapter. Nothing I could fix at the race track so I went home. Later I found that the gauge showings must have been correct so I thought the relief valve in the (new) pump was stuck so I bought I new standard pump and dropped the pan and took the HV pump out. The plunger was free and moving. Anyway, I put the standard pump in and fired her up again. 10W40 Sunoco. Pressure still to high. 82 psi at idle but gets up over 100 cruising. Locked her in for the winter and haven't touched it since. What can cause the high pressure? I have checked the adapter and cut the filter apart but couldn't find anything.