I have a 74 "L" model and converted it to an electric rather than a mechanical spedo so I can't go look at it. The guys I got the electronic pick up from do a lot of spedo work mechanical and electonic. i think they may be able to help you with a different gear or what ever. Might be worth a call or e mail.
http://www.speedometersolutions.com/speedometer_cable.htm
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