It is interesting, I have seen 216 distributors(steel gear) used in 235's with cast cams where the gears were torn up bad. I have also seen the same combo work for years with no problem.
I feel it is best to match distributor and cam material.
The only mismatch I know Chevrolet approved of, and sold as a replacement for all, was to use the 235 distributor with a cast gear on all cams. Go figure.
