I replaced the Final drive in my 74 Bavaria 5 years ago and have never really driven it. I know. But money to get the body done was spent on other things. My question is this, what is the proper gear ratio? How many teeth? I got this unit from a California Company and do not know it's orogin but externally looks the same. Next, are the ZF Auto trannys more reliable than the Borg Warner? This is the 3rd BW I have been through since I stopped driving it. Thanks in advance