M52, s50, s52 are all the same trays. The m50 is different. You'll be fine with either the s50 or the m52 trays, but I would stick with the trays and caps that came with the cams if they are in good shape since the bearing ledges will be mated to the cams.
The s50 cams will work perfectly fine in an m52. The only time there are issues is if you are trying to install into an m50 ... there you need the m52/s50/s52 trays.
2007 BMW 328Xi Touring, 6 speed
Last edited by ScotcH; 08-18-2010 at 01:42 PM.