[RC-Monster Mike]

Yes, you can re-use your xb8 bearings - should be a drop in fit in this car as well.
When using my mount on a Losi, there are no mods needed. This should apply to the Tekno chassis as well. At the most, a small amount fo shimming would be needed under the cd bulks for nut/thrust bearing clearance.
If using mechanical brakes with a Losi(or any other car), both brake levers must be located above the center diff top plate, as the slipper occupies the space "over the diff cup" where some brake levers often go(some cars have both on top anyway, like AE - others have one above and one below the cd top plate).