sorry I disagree....the oiling system is absolutely identical in all motors other than the narrower oil pump drive. I have seen a couple of motors with wear or spun oil pump drives but it is less than 1 in 100 rb26 failures. In fact, go into GTR_Geoff's engine failure thread and find me a single instance where that caused a failure.
All of rb26 series motors can do with some minor improvements for their oil systems....but after 15 years wear on the pump clearances, bearings, crank straightness, rings, pistons, bad tunes, bad oil changes etc etc etc are much more likely to cause issues.