I don't think anyone has asked the following:

Can the 722.6 (5 speed) be installed on a 96 c280 with little or no modification? I ask this because I know the 96 was the last year with the 722.4 while the 97 switched to the 722.6. However I also know the 97 was the last year the inline-6 104 was used before switching to the V-6 in 98. I figure that was a pretty good combination, especially after the bugs of the 722.6 were worked out. I ask this because in the future, if I ever have to replace the trans.... Were there chassis changes/mounting changes for the new tranmission?

Anything is possible, but this is nearly impossible, the cost would probably exceed the value of the car. But regardless of cost it's a bad idea - a 722.4 is a good transmission.

To summarize again:

The 96 and 97 had the same 104 engine and same 202 chassis. However, the 97 had the new 722.6 transmission. Did they make significant changes to the attachment points from the 722.4 to the 722.6? I know, odd question, but I'm curious if anyone knows?