There is lots of information written in this forum about OD's.
My recommendation would be to pick up a 55-59 shop manual which has all the information needed, wiring diagram, trouble shooting, etc. GM used OD's from 55-69 in cars and trucks.
In addition to the solenoid you should have a govenor (mounted on the rear housing) pull cable, kick down switch, relay, and wire loom.
Fred
