[QUOTE=Duke2.6]I think the axle ratio is 3.46:1.

I have a 82 300D none turbo and I didn't like the rpm at 60mph in it . it had a 3.56 gear set so on e-bay I found a 3.07 rear end complet for 85$ and it had 130k on it when it arived I checked the ring and pinon and the spider gears, thay all looked good so put it in and gained 8 mph so at 60 now I'm doing 68.
it's a slightly slower off the line but I stay in gear longer and didnt affect the
freeway power at all and the engine now sounds like it should at 65mph.pluss I gained 3mpg on a tank.I had a gear changer put in the speedo cable to correct the calibration.