I have a 68 CST 3/4 on a 71 3/4 4x4 frame, been in the family since new. I have run Suburbans since 1990. Diesel burb since 98, 6.5 crew cab on a Burb frame since 05. The next version will be late 6.5TD/4L80e/241 in the 84 crew cab on the Burb frame. Gathering parts for the next gen.