I wanted to swap my Granite Mega 4X4 slipper assembly to the 3S brushless set up. I ordered a slipper assembly and a Granite 3S motor mount from what I believe is a Granite. Part Numbers AR102666 & AR102666 . I put it together and tried to slide it into place but it won't fully slide in. I cant get the top latch (since broken, Oops) to grab. What am I missing or are there small differences in the motor mounts/slippers that aren't interchangeable. Picks to follow if I can.