after fiddling with these bearings for some time. i have come to the conclusion that they are a solution to a problem that only half works.
what i have found: i shim them up to zero end float, dunno if that's right, but if you don't, they rattle. after a while, the mounting posts get beaten out by the action of the rockers = end float = rattle. all the worse for having no plastic bushing fitted.
i've tried shimming them with the mounting posts pre splayed, but then can't get a shim to fit without being too loose or too tight.
the amount of movement on the posts is relatively tiny, but it certainly makes a difference. i believe that, unless you were very lucky, the radial bearings would only work if paired with the linked rocker mounting posts as sold by Motoren Israel. in fact, they sell a complete kit including bearings and posts, it's a bit exy though.
being a bit anal about tappet rattle, i will be going back to a stockish setup as soon as i can be arsed to do the job again.
the radial bearing kit can go on ebay. shame someone lost one of the needles somewhere along the line, but it still functions ok, the other side rattles more. tried and failed to get a replacement today, but i very much doubt they are one-offs.