The chassis on the left is the (wide chassis) HARRY HOLTON car, on the right the (narrow chassis) LARRY WOO car. They are basically the same guide flag support and motor box/upright assem. .050 spring steel, main rails .080 stainless steel tubing, 10/ 58 or 60 gear ratio w/ high speed ball bearings and a gun drilled rear axle.1 1/16th x .500 wide tires.