The old overdrives are great, and will do all that you say, but parts are getting scarce. It's kind of a gamble putting out $$ for something that can't really be checked out without at least pulling the tailhousing. The planetary gears and freewheeling clutch parts are the most likely to have problems - thus the most difficult to locate spares for. Be sure the solenoid and governor are there. Anything else, such as relay, kickdown switch or lockout cable will be a plus.
