Does Anyone Run Cleavite "M" Micro Bearings ?

I used to run them and I believe they were recommended by Chrysler for 4spd race race applications. Used the TRW/Speed Pro and the Childs & Albert versions of the babbits. Easier on non-nitrated cranks, they were more tolerant of high shock launches, made of softer material, better embeddability, but shorter life. The auto guys I knew almost always ran the Cleavite 77s with good success.