You will find there's common oiling issue With all the pre-1992 R32 RB26 motors, as the surface area in which the crankshaft fulfills the oil pump was machined too compact, eventually leading to oil pump failure at significant rpm. This issue was solved in later versions in the RB26 that https://martinoibri.win-blog.com/11435316/detailed-notes-on-rb26dett-complete-engine