I can shed some light on the 2.47 gears. If you can get a trans with a 1first gear ratio of 3.87 opposed to the STD.3.68 first gear ratio in the trans. The 3.87 ratio trans can be found in the 90-91 420&560 sels. This will multiply the 2.47 s to make up for most of that lag off the line
do the math its fun
3.68x3.07
3.68x2.88
3.68x 2.47
Then do the 3.87 ratio with the rear end gears.you will see what am talking about.
I have to build.my 83 300d trans. I got 3 whole planetary gear sets "3.87" I don't have a 2.47 gear as of yet. I was thinking of selling this car.but the trans has a noise in it so its got to come.out.
note aslo the second gear ratio in the trans with the 3.68 has a 2.41 second gear while the 3.87 trans has a 2.21 second gear.hope this helps.