I have a picture incoming for this matter...
Giving you a brief description :
I had to extend my Gen.1 Chassis to fit a 1:24th scale model body on it, how I did it, was I used a piece of aluminum, drilled holes, extended the chassis, what I used for my driveshaft at first was a front knuckle stub for RWD, then I changed it too a custom made driveshaft using a model tree, which in fact works wonderful and has not broke yet...
Pictures on their way.
Blade.
Pictures.
Pretty much the third picture you can see the metal piece and same as the second. There are different methods on extending the chassis though.