I used the kit.....But motor mount is the main thing needed. You may or may not use your existing transmission set up. Example, the Lst was a 2 speed. The kit came with the parts needed to convert to single speed, including Diff case without mechanical disk brakes, and proper spur and pinion(s). Battery box/straps. The kit comes with a an electric top plate so that all the oem Losi stuff fits and it is as an Lst Xxl2 E. There are aftermarket parts from other manufactures. Motor and esc.
I am so glad I switched it over. So much more fun to drive in my opinion.