If you are going to run a Brushless set up:
You will need the CRC 3349 Brushless Offset Pod for Gen-X.
Depending on what version of your car you have it could have the CRC 3339 Open-X Rear Pod conv - Gen-X on the car already, At the very least you will need CRC 3337 Red Hex Standoff Open-X Pod which comes in the CRC 3339 or can be purchased seperately.
The (CRC 3338 Left side Bulkhead for Open-X) is the same as the (CRC 3342 Left Bulkhead - Gen-X) but the leading support for the upper plate is machined off. If you want to save some bucks and don't care if it looks perfect you can dremel the alloy brace off and get a CRC 3337 Red Hex Standoff Open-X Pod.
Ashford Hobby CRC 3349
Confussed enough? My job is done here
I would buy a spare CRC 1765 Rear Top Plate - Gen-X 10 as they can break. It is NOT the same as the one included in the CRC 3339 Open-X Rear Pod conv - Gen-X
Ashford Hobby CRC 1765