I am not convinced adding a tcase support will gain anything but add torsional stress to the transmission tail housing when the engine is under load while the tcase is tied down. I suspect that is why GM quite using the tcase support on the passenger’s side on 1973 and later trucks with the aluminum bell housing where older trucks with cast iron bell housings used to bolt the frame.
Now, a rod from the tcase to a bell housing bolt I would do if I could find one. Again, I haven’t ever seen one on a 1973 or later truck with a 205. Later trucks with aluminum tcases….yes.
Here is my stock ’78 K20 wrecker that I inherited when my dad passed away this summer. It doesn’t even have holes drilled into the side of 205 for a side mount or a support rod.
