Viper could be lighter. Carbon mast to reduce weight aloft, carbon hulls and beams also to reduce weight.

Other F16s could also go down all carbon route, (alloy and glass are second grade substitutes). Bigger carbon beams, reinforced beam mounts both to create a stiffer again platform, more hull volume.

Personally beleive AHPC have nailed the specs and pricing on the Viper as a stand alone class. As an F16, it looks to be the quickest product out there whilst carrying too many KGs for the class. A lighter verson of the same product would off course be quicker..... But likely priced out of the market place.