CST Was the top of the line for the 67-70 year trucks. It became the Cheyenne package in 71 and 72. It's only a appearance and comfort package-nothing to do with performance.
Generally CST in the 69s and 70s means carpet, ugraded bench seats and other upgrades in the interior. On the outside you'll get full chrome around the window vents, windshield and rear window and a chrome front bumper. In 70 CST includes a cargo bed lamp. I'm not sure if 69 and 70 CST models included chrome side trim or not but most were equipped as such.
I think the package was available on any model from wide bed models to step models (Very Rarely) to cab/chassis models. CST 4X4 exist also but are fairly rare. 1/2 3/4 and 1 ton tucks could be CST equipped.
About 3-4 percent of 67-68's were CST equipped trucks and about 10% of 70's were CST's.
