Re: il6 merc ignition swap
If you have two complete engines it can be done but it is a lot of work. The intake manifold is different to accomodate the ADI linkage etc, The stator will mount after you change the intake I believe( I have not done it, but I just dissassembled two complete engines with the same thought as you in mind....decided against it). You would also need the backing plate from the ADI system to mount the coils and trigger units on, plus you would have to change the water jacket covers and the throttle arm lever, different adjustment points for idle and timing etc.:%
Not worth the hassle in my opinion, I just rebuilt the best engine, which in my case was the 1975 1150 with distributor.