Depending on your application, you may want to consider the M30B35 oil pump drive gear and chain. The smaller gear will spin the pump faster and build pressure more rapidly, and in theory higher , however the relief spring may limit the second benefit. The B35 uses a spring-loaded tensioner, and while my Euro B34 block had a threaded boss to install one, I went with the shims. I don't remember the thicknesses i used but I seem to recall it needed a few so I ended up getting extras and shimming until I could barely get the drive gear onto the splined shaft. You may want to lok-tite the nut as well. You do not want it loosening, not matter which gear you use.