I'm not completely sure. I know I took a risk buying a jspec engine, but when I looked it over, everything seemed to be in order. The only retarded thing with the new engine was someone drilled a hole in the exhaust manifold that I had to tap and cap off. But that wouldnt affect anything oil related I wouldnt think, even if that cap came out all I'd have is a loud exhaust leak. But I checked all my seals and replaced what looked bad. Only thing I carried over from my old block was the power steering pump, ac pump and intake plenum since I had egr and water line deletion already done.