Hennessey Goliath 650 boosts hp by 55% on Silverado, Sierra

General Motors currently has no answer to high-powered pickup trucks from Ford and Ram, but fans of trucks like the Chevrolet Silverado 1500 and GMC Sierra 1500 do have options. One of those options is the Goliath 650 upgrade that Hennessey Performance announced on Monday. It adds a supercharger to the available 6.2-liter V-8 offered in the…