[D13]

The K case is later model 700R4 in 4wd applications and has all the features noted above. That is not directly related to the rods. The rods are used to help manage the long overhang from the t-case to the bell housing.
The support rods were used on most, if not all, 4wd applications including th400 and th350 units. I haven't really looked for new one because they were so common in the junkyards. IIRC they generally run to the engine mounts.