It should fit. The bell housings should be the same.
The torque converter that came with the 722.3 must be used though.
A torque converter from a 722.4 wont fit on a 722.3

The earliest W124 with M103 3 litre engines used the 722.4.
Later on the 3.0 litre engines changed to the 722.3 while the 2.6 engines retained the 722.4.