hi
you have to use the d4 drive shafts because the bmax ones are too large, however the hub end is an almost exact match you just have to use a thinner shim behind drive pin.
the xray out drives are the same size as the d4 as i have those as well.
if you use the ones from the multi diff you can also have a fixed oneway and spool
the bearing size is an issue as a 10 x 19 is not available. i got round this by using the plastic bearing carriers off an xray tc, these are just about the right size, although you have to trim the width down.
the last thing is that the diff gear is only 39t instead of the bmax 40t so the front ends up slightly over driven dont think this is an issue.
if anybody wants to i'll be at broxtowe on the 6th and worksop on the 20th. just look for the most tastefully painted bmax
cheers andy