@jiggity76 - that is impressive work. Have you replaced the oil plug gasket/o-ring?
When bought my Cutlass in 2007, I told a mechanic that It had the 3.4 DOHC, he advised me to sell the vehicle. He had a Pontiac with the 3.4 and hated working on it due to the tight clearances and the added complexity the DOHC configuration added to the engine.