If the oil cooler is leaking oil into the coolant you need replace it not bypass it i would get the Cadillac catera oil cool to replace it they use the same engine in the car.

Does it provide any lubrication to the top end?

No it it cools the oil in the engine think of it as a oil filled radiator submerged in coolant.The oil flows thru it and thru its fins and being submerged in coolant cools the oil in the engine.

Ok thank you I was just trying to avoid pulling the intake to replace the oil cooler, I did bypass it but now it's acting like its starving the top end with oil. I pluged the supply and return lines to the cooler so maybe it's not getting any oil circulation .

Oh you plugged them not good sounds like thats your problem best to put a new one in.That engine was designed to use that oil cooler you dont want to damage the engine.