Underneath you find the different gearbox codes of the syncro gearboxes and front differentials.

In the column between R-G and Achsuebersetzung you find the final drive. You will find that this final drive is the same for some gearboxes. On these gearboxes only you can use the front differential that goes with another gearbox. Or, wih other words, if you have a broken gearbox or front differential you can’t just put a gearbox from another syncro in it, if the final drive doesn’t match the car will jump a bit and then either the diff or the box will break.

If you want to tune your syncro and make it perform better you have to go for a gearbox with a “short” final drive : in this same column these are the boxes with the highest number (6,03). Cars with these boxes are very powerfull offroad (a lot of torque) but the top speed is very low. Cars with a “long” final drive are fast but have less power offroad.

When tuning a car by putting in E.G. a TDI engine we will not only reinforce the gearbox but we can also make your 3rd and 4th gear a bit longer to gain additional topspeed.

Because what people don’t seem to keep in mind is that the gearbox is the limiting factor when it comes to top speed. You can put in a very powerfull engine in your T3 but when you don’t change your final drive you just won’t drive faster (unless your new engine can make a lot more revs then your old one).