Hey Joe,
Whats up...
The Capricorn does not need any parts from others cars. it is more about personal preference. For that matter people running Xrays use transmission parts from the Capricorn, if they personally want to. It is not done out of need, but sometime people doe things since they are cheaper or easier to get for some reason. Capricorn now has additional choices for the springs. when it first came out there was only 1 set, now there are 2. The car stock with a simple set-up will work great out of the box. Trust me on that. Nothing against the Xray or other cars, just do not want to think the Capricorn is a second choice to any other car. The Capricorn has it all and performs great.
Good luck on your choice,
DJ Apolaro