I am fitting a Tremec TKO 600RR (0.83 5th) to my 68 Iso Grifo 7 Liter. This is repalcing the 4-speed Muncie M-21 it currently has. I have 3.31 axle and tyre size is 225/70VR x 15. Can anyone tell me what speedo gear I will need in the Tremec (it is a mechanical-drive speedo)?

Also, where can I buy the McLeod - or is it Hurst now? - shifter that has a lower profile than the standard Tremec shifter? I believe there a number of different offset stubs you can get to alter shifter placement? Won't know what offset side to side and fore and aft until I get the two boxes side by side on the floor.

Thanks,
Chris