Losi 8ight e conversion

[gnr racer]

having decided on motor/esc & lipo, could i seek some further advice from those in the know..
do i need to source a plastic spur gear as stock on an 8e or can i run a metal spur? also is there any issues fitting a castle creations motor to a Losi motor mount? as i would rather use the Losi conversion kit,i know Marvin has commented that the Losi battery tray is a little high but i can live with that
If there is anyone out there who has done this conversion with the hardware mentioned any advice would be gratefuly received