Side windows for improved visibility were introduced in the next version, and the K 8B, by far the most numerous variant, has a larger one-piece blown Plexiglas canopy.

The fuselage is a welded steel-tube structure, with fabric covering over spruce longerons and a glass fibre nose cone.

Karl Striedieck of the United States made a 767 km / 476.6 mile ridge flight in an K 8B to establish a world out-and-return record in 1968.

A motor glider conversion of the K 8B was developed by LVD (the Flying Training School of the Detmold Aero Club) similar to their conversion of a Scheibe Bergfalke IV known as the BF IV-BIMO, in which a Lloyd LS-400 piston engine mounted in the fuselage drives a pair of small two-blade pusher propellers rotating within cutouts in each wing near the trailing edge.

Another motorglider conversion was used by "Vestjysk Svæveflyveklub" in Denmark: it had a small Wankel rotary engine mounted in a nacelle on an aluminium stick above the main spar.