It can be done, however the mounting brackets are not in the correct positions to line up with the M103 intake manifold.
On my W124 wagon, I carefully cut, modified, and relocated the M104 rail mounts to match the mounting points of the M103 Intake. T rail is stainless so some fabrication and TIG welding is needed to make it fit like "factory".
The injectors fit perfect and line up just fine.
Of note, you'll need additional high pressure fuel hose, fittings to make it safe and have reasonable fuel supply/return routing. The air filter housing does fit, but is a snug fit, the fuel regulator does not interfere with anything.
