A friend had the Raider and it is the same part for the rocky, as darren says, you just had a longer layshaft to hang the chain on for the rocky's 4wd.
Just think, Kyosho had a production mid motored car out in the 80's, who'd have thought it would be such a popular concept!
In this picture you can make out the layshaft just behind the motor and the rocky had the chain on the opposite side.
I reckon the steering blocks in your other topic are also off the raider.
