seems to me the condensor would work fine. Be sure you locate it out of harms way,and it might be good to install an electric cooling fan to help it at low speeds,and I'd also consider an adjustable fan thermostat. (tramsmissions run quite a lot hotter than engines,so you'd need to be able to adjust the start and shut off temp.)
Speedo gear should be operable,if not accurate,with the speedo cable.
driveshaft you'll have to have built;the truck uses a larger u-joint than the car the tranny's out of,and the length will be different.
You should be able to use an aftermarket floor shifter,you might get lucky and find one in the wrecking yards. They mount to the floor and connect to the tranny with cables,so the installation is pretty easy.If you can score a ratchet type shifter it's easy to either build a tower to mount the shifter on or extend the shift lever to put the control within easy reach.(You might also be able to use a factory GM floor shifter but it might take a lot of mods to work with your application and is harder to change from the stock mounting/tranny location relationship.) On the older stuff I worked on,I used to just braze a piece of 1/4" rod to the shift arm on the tranny,but then,that was not without it's risks and problems.Definitely not recommended.
Speed
