Atco DragWay Roy Hill in the Duster takes on I believe that Richie Zhul in the smallblock Vega. The Hemi Dusters usually where at 430 cubes & the Vega's where usually at 331 cubes. The Vegas where 700-800 pounds lighter mostly due to the weight added to the Hemi's. I think it was 7.5 pounds per cube for Hemi cars & 6.25 pounds for smallblock wedge head cars. This lead to the development of the 396 & 366 cube Hemi's