There's engineering/chemistry company called Archoil (
http://archoil.com/) that came up with a "friction modifier" made from a boron/potassium mix thats better coating and slipperier than zinc without the negative effects. They recommended for flat tappet cams in place of zddp additive.
Have any of you tried it? Have you heard of archoil?
It's $36.00 at amazon for 16 oz. Takes 1.2 oz per quart of oil (7.2 oz for 305D), so about like putting another 1/2 jug of rotella in I guess.
They also make a boron based grease with a low "washout" rate of 0.5. The normal bearing grease washout rate is 3-7. Amsol is 1.70.
I'm thinking of using it in my hubs when I work on them this summer.