Why do you believe top end wear is a big problem? The heads have oil pools that the cams splash around in, these provide oil during the first seconds of running when pressure is low.
Aware of the insanity of risking the crazy oil thread curse, I still recommend the Rotella T6. SAE5 is too thin for these engines but it thickens up quickly as the engine heats... and these engines heat up quickly. I don't recommend full throttle to redline on a cold engine with any oil.
Synthetic oil is not some mad science experiment. Molecules very similar, maybe identical, to those in petroleum oil are assembled from smaller molecules of a base chemical. The difference is that synthetic oil molecules are very consistent, refined petroleum oil has many different molecule types and sizes. The consistent molecular structure allows consistent behavior over varying temperatures.
Using diesel oil gets you increased zinc and phosphorous, both are good for reducing wear on our slipper tappets and cams. Automotive oils have had these reduced radically as modern engines don't need them (and they cause pollution somehow... maybe crud up catalytic converters or something?).
So basically Rotella T6 has worthwhile benefits. There are stories about problems using synthetic, presumably true. I have used true full synthetic oil (most big brand synthetics are actually a blend, "synthetic" on the bottle means squat... Amsoil is real full synthetic, the super expensive European brand synthetics in bike shops are, I think Spectro synthetic is too) in SOHC4 engines for many years with zero problems. The first time I poured it in, that bike immediately idled and ran better -
and quieter. You may find problems, the common one is oil leaks getting worse... all I can say is that this hasn't happened to me.
