First lets start with the basic Pro-track chassis. This in itself is a very good runner. One of the things that drew me to this model were the wheels and tires. They look a little like old aluminum deep dish mags from the 70's that most of us grew up with.
I wanted to fit the chassis on a 1/24 AMX body. After a trial fit there were two things I found that I thought had to be modified. The first was the wheel base length. The Pro-track chassis ia a great chassis but has limited adjustability. The other problem was the guide being way out in front of the car.
To make the wheel base fit the body, the front wheels had to come back about a 1/2 inch. Since the axle holding tabs were not long enough, they had to be extended back farther into the chassis. The trick to this is to solder in two pieces of flat brass right in back of the original tabs. This extends the tabs back far enough to allow for the new axle location. Now it is easy to locate where the new axle position would go in the brass plate. Once this is found, drill two holes to accommodate the axle. Depending on how far you move the front wheels back , you might have to cut away some of the side mounting plates to accommodate the wheels in the new location. This is shown in the picture below.
Now to move on to the guide mounting tab. First unsoldered it from its original position. It will be relocated back to where the square hole is in the front of the chassis. The square hole will need to be widened to make room not only for the guide but for the swing of the guide. Once the square hole has been opened up re-solder the guide holding tab back in its new location.
Note: make sure that the guide will not hit the front axle.
In my application I also turned the guide holding tab over before I soldered it back in. This gave me the extra clearance that I needed between the guide and the axle. (I did not realize this at first so in the early pictures you will see the guide plate higher.) The picture below shows the plate turned over.
The above photo shows the cut away of the extra brass in front of the axle. This can be done easy enough with a dremel. I think you will find that the guide in its new location will not only look better, but will also give the car more realistic handling.
To fit the wheels under the car there is some adjustment that will be needed to be made, using the white axle spacers provided with the chassis it is easy to do. To make this cars stance narrower just trim the spacers down and relocated the tires further on the axle. In my case this was still not enough. I really wanted the rear tires to fit under the body. To get the correct look I wanted I had to trim off some of the inside of each tire with an exacto knife. I then put each wheel on the axle one at a time and ran them in a drill. Using the drill and a file I turned down the inside part of the aluminum wheel until it was even with the width of the tire. Trial fitting the tires back on the axle and into the car showed a perfect fit.
Overall for just a litttle work I found the look and performance achieved was well worth the time spent. If you have any questions about this project, please feel free to contact me at firstname.lastname@example.org