I just converted an LX ultra comp to electric. I used the motor mount and battery tray from the LX1e. Everything worked perfectly. I replaced the rear center diff brace with the LX1e motor mount. The only thing I had to do was to widen one of the holes for the motor mount screws in the chasis because the stock diff mount holes were slightly off. I just slotted the existing hole and it worked fine. I also used the rear brace from the LX2e to replace the stock rear brace from my ultra comp. The battery tray did not align with many stock chasis holes so I improvised a bit and got three of them to align with the battery tray holes. This is just enough to support the tray with my (2) 2s packs.