never seen this engine run. Ive sourced another pump a JP highflow pump for $100 i'll wack that on 2morow and if its still no go then sump is coming off
Have you checked to see if your 202's pump has a pressure relief valve spring fitted or valve may be stuck open.
If the engine was running ok before, and all that has changed is the pick up, then there's the problems
My holden book quotes 310kpa max oil pressure @. 1500
never seen this engine run.