 The engine change provided a large internal volume for fuel storage, eliminating the need for the T-33's wingtip tanks, but tip mountings were retained to accommodate optional auxiliary fuel tanks if desired.Other modifications included inboard wing leading-edge extensions, the replacement of the tip tanks with winglets, a new canopy with one-piece windshield, revised nose geometry to improve visibility from the cockpit and to fair into the T-33's lateral intakes, new tail surfaces with a mid-set tailplane (although the original wings were retained), and new avionics.The Skyfox was designed to be produced entirely from kits of components.