The M103.983 (3.0 SOHC) and the M104.992 (3.2 DOHC) I would think would be interchangeable by physical space. The trick would be retrofitting all the electronics that go along with the M104.992 (3.2 DOHC) motor. But that is far more do-able than a V8 swap. The 3.2's are also much more common than the M119 V8's. If Benzmac still has the C36 motor and tranny for sale that might be an option for you to consider. You'd have to talk to Benzmac or the other techs regarding the finer points of the swap. Another option to throw into the mix...swapping the M104.980 (3.0 DOHC) onto the M103.983 block or a swap of those two engines all-together. You will want to talk to Benzmac or another tech regarding the fine points of such a swap (and if Benzmac still has the C36 engine/tranny for sale)

Just an idea...Lee