Thanks Joe and Dave for the great input.
The picture at the top of my last post was taken before I started digging through my parts bin for alternatives. The spur gear shown is a COX 48T. The largest I could find in my box or on the web was a 50T 48P brass gear with some lightening holes. It was only slightly larger than the Cox because I believe the outside diameter is limited as Joe points out by the overall rear wheel tire combination which is typically 1.25" or less. Luckily for me I chose the Dynamic rears which come in at just about 1.375" which leaves me an opportunity to go a bit further before I create a car that chatters it's way down the track and get's me thrown out of my favorite slot car track for life! So I am planning a trip to the RC store over the weekend. If someone is aware of 48P spur gear somewhere between 1.25 and 1.3" I would love to get my hands on one. It is often hard to get parts at most hobby stores unless you have a a particular brand and product model number.
Unfortunately I have already limited my options somewhat significantly by my body build. The pocket for the motor and the mounting for the body are firmly attached to the body and so I want to eliminate all other resolutions ahead of tearing it all out and starting over.
I'll try to take a picture this weekend showing the situation to make it more understandable.
I love the idea of adding a brass tube over the rear axle soldered to the bushings to keep all this lined up properly. The chassis is not inherently rigid and this will help a ton.
Joe, I would love to see the Ala Kart! Here is a couple pictures of my Bandit build. Probably one of favorite cars from the sixties.
The finished car
During the build showing the chassis