Originally Posted by oldnwise

F103RX Kit included some hop ups for the front end that are not on the RM ....
http://www.tamiyausa.com/pdf/exp/58194e.pdf
- Link Type Front Suspension Arms (Part 53258 now discontinued)
- 3.5mm Offset upright (Part 53259)

RM has a one piece thrust bearing (RX used two washers over a case of ball bearings)

I think the rest of the parts are identical.