In some respects, the NAC-60 was a scaled-up variant of North American's bomber prototype, the B-70 Valkyrie. As with the B-70, the design of the NAC-60 did not include horizontal stabilizers at the tail structure, but did retain the high-mounted canard above the cockpit area, and the box-like engine area under the fuselage. The use of high-lift devices on the leading edge of the wing lowered the landing angles to the point where the "drooping nose" was not required, and a more conventional rounded design was used. Compared to the other designs, the rounded nose profile and more cylindrical cross-section gave the NAC-60 a decidedly more conventional look than the other entries. This also meant it would fly slower, at Mach 2.65.