Oil Press.

Another first timer,My wife bought me a 1983 Elec.Glide Classic for my B'Day 3 years ago.Taking a Sunday ride with some friends & came to a red light.While waiting for the light I heard something that didn't sound right so we pulled into the parking lot just to our right & I shut it down.Had loaded it up & took it to the house.I fired it up where it was no other noise so I could hear only my bike.It didn't take but a sec.I turned it off,it sounded like a lifter but I wasn't sure so I hauled it to the shop.I was right,I told them to go ahead & rebiuld it so they did,bored it a little new piston's rod's bearings oil pump & what ever.First time Harley owner,wanted one all my life but didn't want to spend the money I always wanted to spend it on my wife & kids.Any way they told me to bring it in when it had 12-1500 miles on it.Maybe somone could tell me whats right & not.When I first fire it off it has about 40-45psi oil press.when it gets to what I call running temp.it drops to 20-28psi.is that ok or not? I can't let it sit for more than 3 days if I do when I do start it oil pumps out of the rubber line that comes from below & plugs into my air breather.The most that has come out so far is about 1/3 qt.this isn't new it was doing it before it was rebiult.Many thanks for your help.