How are you measuring the oil pressure ...with a gauge or on the light?
The reason I ask is based on my 1st ever engine rebuild ...1969 1275GT I had at 17 (they were worthless then) - full engine rebuild at the machine shop with me assembling - back in the car plugs out no pressure with the light, so a quick tow with the plugs still out, still oil light on - royal bollocking from my Dad 'you prat, you've put it together wrong and missed out the spider' - me practically in tears ...then I swapped out the sender unit and hey presto we had pressure ...the sender was faulty not my workmanship - my old man 'you should have checked that earlier'! You cannot win with him.
Edited by DomCr250, 11 January 2019 - 11:08 AM.