Stock oil pressure. Too high?

I have a 1990 MJ. 4.0

I run 10W-30 in it, which is about 1000 miles old now. On cold starts (about 40 degrees) the oil pressure goes to about 70PSI. Then slowly drops down to about 30. If I run i hard (wheeling) itll drop to 20psi.

Today, I started it after work (probably 35 or so) and it pegged. A little past 80psi. Is that a bad thing?

A couple years ago I got a new motor (previous owner did this) reman block. And the truck only has 105K on it, probably 10k since the new motor.

Should I maybe use 5w-30 for winter? It gets cold in maine.

come on? What other info do I need?

For that old a MJ I would look at a bad guage sending unit or a bad wire/ground.
I would think that a 5w-30 would work well in cold weather like you have in Maine.
Wayne