This is the one I purchased to install on my 72 K10.
https://www.amp-research.com/images/...MPIS-75104.pdf If the inner rocker is the same as the truck it should work. Provides about an 8" drop from the rocker where you step in. The thing I like is that this one fully retracts behind pinch weld at bottom of rocker. Install should be pretty easy, the top of mounting flange needs to be trimmed down to bolt holes. Drill through pinch weld for lower holes and install riv-nuts in inner rocker for upper bolts. I also have some 4 degree shims to go inbetween the inner rocker and linkage assembly as that surface is slightly angled. Hope to have install pics in my thread in the near future.