I realize this. But at one time mercedes did mate the M103 type CIS injection to the M104 long block, ie 300SL & 300CE.

My question is what is different in the configuration. Provided the CIS injection is the same on M103 190 and 300 cars as it is in early M104 cars like the 300 SL/CE.

The intake runners on the intake manifold to accomodate the M104 Head

or

Are the ports different on the early M104 Head to accept a M103 intake manifold with CIS?