Hey Gam, My Mitchell system only goes back to 83 but 83 pickup with a 350 says normal oil preasure should be 35 to 40 lbs at 30 to 40 mile an hour (whatever the hell that means LOL) good rule of thumb
is 10 lbs for every 1000 rpm, of course if ya got 5w30 in it It'll be lower specially when it builds some heat......