This is my take on it with only seeing pictures of the engines so far.

1) I estimate the engine will be about 7" longer, which means it wont fit lengthwise without moving the radiator. You have about 1" to move the engine back. If you take the one 1" you should now have a shoe horn fit. Radiator may have to be removed and replaced with a thin single core unit along with two small electric fan cooled radiators on each side.

2) It looks like the intake manifold may hit the brake booster. The brake booster may have to be moved under the fender and actuated with a bellcrank and linkage.

3) Where the engine bay in the 107 gets narrow is down about exhaust manifold level. The M-120 has wider heads but it is also a 60° V instead of a 90°. Hopefully these two facts wash out.

4) Totally unknown to me is the placement of the oil pan sump in relation to the sub frame. These can be modified but I'd rather not. There are also 2 oil pans for the M-120 one for the SL and another for the S. This widens the choices. But I belive the SL one (Forward Sump) is more likely a better solution.

5) Engine height unknown

All the reast of the stuff is the standard swap engine problem.

John Roncallo