Ques about oil pressure
 

I have an 85 GS and was taking notice of my oil gauge. I notice at idle , 900 rpm, the oil pressure is a little over 30. And when I am driving at 3000 rpm and over the oil pressure is a little under 110. Is that a good range for this engine?

perfectly normal, are you going off the stock gauge?

at 3000rpm it should be about 60psi, unless you have an upgraded regulator or shims, etc. Make sure your gauge is accurate.

high oil pressure is better than low pressure, but I would think unchecked pressure could cause longevity issues with the oil system as a whole.

Yes, I am reading the stock gauge. It seems to move when I accelerate or deccelerate. I assume thats just the change of pressure in the engine.

If it's like the 2nd gen, it's supposed to move. If you're using the stocker just keep in mind that it's 25+ years old so don't expect it to be super accurate. On my FC I just use it as a tool to tell me I have oil pressure.

I've never personally come across a stock oil pressure gauge that worked correctly. Get an aftermarket mechanical gauge, that'll be way more accurate.