oldbluetruck,
First, let me say that I do not know much about your year/series of truck (55 2nd, I assume).
In earlier HydraMatic trucks there was not a bell housing that was separate from the transmission assembly (thus, the manual transmission bell housing would not be of any use with a HydraMatic).
In manual transmission 216/235/261 trucks, if a factory 4-speed transmission was installed, there was no pivot pin sticking out because there was no need for a column-mounted linkage. Additional useless information: on some earlier 4-speeds there were also no holes on the upper steering column for the 3-speed shifter-bracket under the steering wheel.
As pknauth said, a stock or fabricated pin can be added.
Tim
