The deal is that on all buses with a type IV engine you don't need to support
the tranny.  (also on split windows) It has mounts at the front and rear that
hang it from the bottom of the bus.  On bay window buses that have a non-Type
IV engine ('68-'71?)  there is no rear tranny mount and it needs to be
supported.  Both Muir and Haynes got this one wrong.  You certainly can't
hurt anything by supporting it, but if you have a rear tranny mount on yours,
don't bother.

Sean Stueber