Silhouette racing cars

[tk9650]

Does anyone know what the rules are regarding silhouette body racing cars? I am aware that the wheelbase and location of the engine must be that same, but I was wondering whether if a car were originally front wheel drive, would I be able to convert it to rear whell drive?

I'm afraid I haven't got a copy of the RAC blue book, so any comments or suggestions would be gratefully received

Tom