W126 engine swap, 5.0 to 5.6

[Ben12345]

I dont know if any of you recall, but I was having problems with my 5.0 V8 M117.963 using water. Having replaced head gaskets, rebuilding the heads, refreshing the intake, i'm still getting coolant into the exhaust.
So, I purchased a 1988 560SEC to use as a donor for the M117.968 high output 5.6 V8.
The 5.6 obviously has KE jetronic, and I'm pretty sure that my existing intake and fuel injection will bolt up to the 5.6 engine, to eliminate any need for the computer.
My concerns are the distributor and the EZL. Would it be best if I transplant this system into my 500, or use my old style distributor and ignition unit on the 5.6?
I'd also like to swap the switchable transmission from the 560 into my 500 at the same time. How feasible would this be?

Any other things I should be aware of?

Regards.

[mbdoc]

Easy swap....Ignition timing Can't be adjusted on the 560 system so I would go with the distributor.

Intake manifold & distributor should be the most difficult part.

The tans will work just fine.

[Ben12345]

Sounds good. I take it there is no advantage to the later style ignition system then? I like the idea of it not being adjustable though, so there is one less thing to adjust and troubleshoot. But I also hear that the EZL's are fragile and expensive to replace.
My 500 currently doesn't have the switchable transmission. Is the wiring easily swapped over?

[mbdoc]

I'm not familiar with the term switchable trans...

Are you talking about the "B" lock-out?

[Ben12345]

If you look here:
http://www.carsearchuk.co.uk/showPicture.php?image=/carimages/i315_5m.jpg
You can see the switch above where B is located. Its for switching between 'Sport', 'Winter' and 'Normal' modes I believe.