I have a 1968 250SE with a 4 speed manual trans and a 4,08 ratio rear gear. Great running car but not so good on the highway or with keeping up with traffic in first or second (too low a ratio) gears.
I also have a spare 4,08 complete rear assembly, a 3,27 ring and pinion (numbers match) and the correct carrier for it (came from same source). I am a former hot rodder and familiar with setting up U.S. versions of ring and pinions for proper gear position/pattern. I have the FSM for my car. There is nothing that I can find in the manual regarding how to set up the ring and pinion to get the proper positional relationship and wear pattern necessary. I do not want to disassemble the donor rear until I have proper specs.
Right now the only thing I can do is measure rotational resistance with an inch/pound torque wrench.The FSM sindicates this should be "20-25 cmkp". I have never heard of 'cmkp' as a unit of measure.

Does anyone have any info on this?

I am also looking for the ring gear-to-carrier bolts.Does anyone know of a source?

Thanks!