722.3 transmision R.P.M's
 

So, I crawled up under the car today. I have a 722.300 transmission. Looking that tranny up I have a 1:1 4th gear. If I am reading that chart right. I have noticed while driving this car that the revs seem rather high when you reach 4th gear. I am, however reaching 4th gear. I tried out some suggestions found on this site. I am really surprised the R.P.M.s are that high in 4th gear. Oh, it is a 85 280SE Grey market.

The question/comment is, If the final drive is 1:1, than my "rear end" gearing is 3.68 the same as my final output? Wow, a tad low ended Mercedes... I am correct here?

Sounds right. All MB 4 speed auto's were 1:1 4th gear I believe. 3.68 is indeed a bit much for a 280 realistically, it would probably do fine with a lower unit like a 3.07, acceleration would be a bit reduced though but with the benefit of lower highway rpms.