I know, the RC-Monster CD unit would work perfectly and its a good price, just havent really gotten around to it- the GorillaMaxx chassis rails need replacing with something more sturdy that incorporates a CD unit / motor mount too, rather like:
http://www.rc-monster.com/forum/showthread.php?t=19388
but tied to the chassis rails & bottom plate. Im gonna let the Candyman finish his current project though & do his Emaxx 'Razor back' chassis & see what I can come up with. Wont be anything too radical, mainly beefy & symetrical- long time before that happens though so I'll carry on with the old tranny (

) for a while yet..