XRAY - Model racing cars

Can someone explain exactly what was changed on the XB8EC to get more rear weight bias? Is the chassis longer? Are the engine mount screws just moved back? And how were changes made to parts like the center diff and center drive shafts to keep everything aligned correctly?

I have heard conflicting reports on exactly what all changes were made to get more rear weight and I can't really tell from the pictures. It would be great if someone in the know could explain.

Center driveshafts are now equal in length.

Yes, the engine is moved towards the rear of the car.

I already know the engine is moved to the rear of the car. What I don't know is how this was accomplished. Is the chassis longer or are the mounting points for the engine just in a different location? Also how are the other things changed to get everything aligned back up?

You don't need to do that to the front body mount. A lot of guys put a rear body mount in the front or shim it as you described to prevent the nose from breaking off. The stock location is hard to get to if you run the Pro-Line Crowd Pleazer 2.0 with the humps in the front, so they move it back a bit to make access easier and to prevent the front from cracking off .