X6 driveshafts?

[Lee1972]

I'm sure this will have been covered in the past; I'm currently in the throes of converting my son's old B4 into an X6 but i've noticed that I pull the axle on the rear wheel through the hub to put in the spacers and drive pin the dog bones are resting on the edge of the outdrives. A fellow racer kindly informed me that we need a set of B4.1 cva driveshafts s they are longer but i've also heard that you can use Losi ones can anyone please advise?