The two wheel drive trucks and buggies have a battery box mounted off of the back of the car to add weight to the rear end for traction. The two wheel ST and MT parts should interchange with the ATX with the exception of the shock tower which you shouldn't need to replace.
Without lightening up the front end and adding weight to the rear you will have traction problems especially without the slipper clutch.
As far as which is better it depends on how and where you run your truck. Four wheel drive will allow you to stop, accelerate, and handle ruffer conditions better than two wheel drive. Two wheel drives are usually faster (top speed) and corner better than four wheel drives.
CEN makes a four wheel drive conversion kit but I don't know about a 2 wheel drive kit. Try emailing them to find out.


rolland