[Graham]

Hi 
Just coming into this debate questions etc. 
to be clear 

If I take a SCX car rally and swop the chassis to a 3D and put metal wheels all round what class does this come under?? 

If I have a avant and change the motor and wheels what class is this ? 

If I have a scaly and change the running gear same chassis semi modified. What class ?

I like defined examples just to be sure as I am a little dot confused at the moment.. 

Looking for clarity here please ?

SCX car with 3D chassis becomes a Class B car

Avant with motor change remains a Class C car

Scalex Car with change in running gear becomes a Class B car