NB, you guys have the advantage of being in Europe. I'd love to drop a lower value rear in my 240D, 1st gear is just a waste of time in it. Tell me where to find the mythical 2.47 and I will be eternally grateful
Though we are getting slightly off track.
Frank, your car is fine, it is doing what it's meant to.
the 240d will be better of with a 2.88 or 3.07, esp if its an manual, automatic is a tad different, id start with a 2.88 if thats the case (found in the om617a cars in 1985) and see how it turns out, its al down to how much slippeage you have.
i had a 2.65 LSD in my 240d (the torn one) and it worked but barely, it was to slow, althou that engine is slow as hell, (gets beeten easy by the other 240d even thou that has a 2.88)
might work with an automatic and a healthy engine. it will still be slow, and increased slippage in the auto-converter
the 2.47 is in the 380SE w126, in an manual car best suited for a more torque happy engine than the 240d
differentials, gear-ratios and compatibility | Mercedes-Benz turbo
and the w126 with the 2.47 differential.
observe that the speedometer is WAY of, due to the diffratio, 1600rpm = 65mph
the diffs from straight cylinder engines up to and during 1985 will work on any other straight cylinder engine chassi (w115, w123, w116, w126, r107)
the v8 has a larger flexdisc, and you have to swap the yoke, with al the work that goes with that. so a w123 2.88 is imo the best start, relatively easy to sell to.
Europe isnt an advantage, atleast us in sweden has almost no w123 turbodiesels, and thus, almost no differentials to source for a swap.