There's a frequent oiling dilemma with the pre-1992 R32 RB26 motors, as the surface in which the crankshaft meets the oil pump was machined as well tiny, at some point leading to oil pump failure at high rpm. This issue was fixed in later on versions with the RB26 by https://buyrb26engine23108.idblogz.com/31693586/not-known-details-about-used-rb26-engine