The build continues as the motorhome's 400 V8 gets supercharged, and Finnegan, Cotten and Newbern attempt to make their '78 Class C GMC hang the tires in the air against pro wheelstander Mike Mantel and his Little Red Firetruck. The guys solid-mount the rear axle, shift weight and construct the largest wheelie bar we've ever seen, but will it all work?