No Redline never gave syncro problems that I have yet to discover, but neither does VMX 80 and why pay such a high price for oil when the much cheaper Castrol does the same job? The diff whine is there regardless of the oil used. So I will pull out the gear box, change all the oil seals, that are leaking expensive Redline everywhere, and adjust the diff to hopefully get rid of the whine. The only problem with Redline for every day use is the cost for what I see as no gain. Perhaps the expensive is justified for competition use as Alan has explained.
Re synchros, that's what I thought too. Fair enough re the cost! I'm leak free and change every 6 years or so (maybe 30,000 km, most these years seeming to be cross-Australia trips!!) so the cost per km is small. You've reminded me of the pain of changing that selector rod seal with the gearbox in place and no hoist...… Thanks for the reply.