Hi,
I have a complete E58 with drive shafts. And a complete E51 in my AW11! I would rather get the E58 all readied up and THEN take my car off the road, but I need the E51 selector to put into the E58 box. Interestingly I've read that E58 is 3.9:1 final drive and E51 is 4.3:1. So 100kph in second gear at a smidge over 7500 should be possible, that would make for a good 0-100kph.
What did you mean about custom shift linkages? Does somebody make a set?
I thought about longer shifter cables, but this has the problem that the cables would have to be VERY long and go around the engine to get to the box at the right angle/side.