i just measured the track width of my truck, and loked up the impala/caprice dimensions, and the impala/caprice track width.the impala/caprice has a 62" track width, and if i measured mine right, it has a 50" width. i dont know if that was supposed to count the width of the tires or not, but i measured like this:

{left wheel}<tape measure>{right wheel}

from the inner sides of the wheels. if i'm wrong in my measuring, and i probabally am, then there ia a good chance that my truck could fit on a caprice chassis with a 350 with relative ease.