In 1976 GM went to a half-cab design on the K5s and made the factory rollbar an option because the trucks now had a fixed roof. We don't ever plan on rolling our K5 (who ever does?), but if it should happen we wouldn't want to be without the extra protection that you get with this Smittybilt interior tube bar. The three-piece kit is $170 and installs without removing the hardtop. The only problem is that our Skyler soft top won't fit over the tubes unless we have it modified.