A std size servo is going to be a tight fit with the pinion I just took a look and you will have to remove the rear servo mount or flip the rear mount and bolt it to the outside of the servo to get it in there?
BCE is working on an extended chassis with a std size steering servo.:)
Here is a link to the picks of the new chassis and top plate
http://www.truggyracers.com/forum/in...c=12866&st=105