I understand that a 3 speed with OD was offered in years 58-59 years. Are these transmissions fairly common? I have a 1953 1/2 ton 3100 and want to swap it out for an open drive train from a 55-62. With the overdrive mated with the 3.90 axle, will this give me good highway cruising speeds around 70? Also, was the OD unit offered these years mechanical or electrical? I have never seen one so my fear is that they are rare and very expensive if one is available. Thanks
