Yea, its the RCM motor mount. I had a US Sport as well, which I just sold. I was going to do the same thing as you and try to upgrade it, but getting a new kit and selling the sport seemed easier.

With the manual brakes, the brake servo is plugged into the 3rd channel and I did some funky mix thing with my DX3.0 to make it work. I've programmed the MMM to have 0% brakes, so when I apply brake it actuates the servo. I forget what exactly I did, but if you have a dx3 I can look it up.

Took some more photos with the battery packs in:

ST-RR


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