Any knowledgeable W124 gearbox people on here? Advice sought

[sim16v]

Currently looking at replacing a faulty auto box in a W124

Gearbox codes are as follows:

Faulty box
Transmission: 722433 [transmission Type = GA] E280

Possible replacement
Transmission: 722434 [transmission Type = GA] 250D

I have been told they are interchangeable, but might possibly need to change over the vacuum modulator from 722.433 to the 722.434.

Would the box work without changing the modulator, and would the matching prop be required?

Thanks.