Swapping between ignition systems (550)

Hi everyone, my first post on this forum! Apologies if this topic has been covered before - I've run a search and couldn't find anything.

Does anybody know if it's possible to swap between the different ignition systems that were fitted to the 550 engines throughout their life? The situation is - I have a Z550F (ZR550A model) with a rather tired engine and gearbox. This model was fitted with the semi-electronic type of ignition system, with the IC ignitor but advance controlled by the ATU. I have the opportunity to acquire a Zephyr 550 engine locally for a good price. The only catch being, as far as I know, the Zephyr engine uses the later fully-electronic ignition system that has a more sophisticated 'black box' and does away with the ATU.

What I want to know is, is it possible to directly swap the ATU and older style pulsing coil onto the Zephyr engine, so I can continue to use the stock Z550F wiring?

Many thanks.

Chris, as someone who put a Zephyr ignition on a 81 kz750, I "think" it should be just a matter of unbolting the zephyr pulse coil and timing rotor and installing the ignition system from the z550f.  The crankshafts are identical between the two bikes, so they have the same timing-locator pin in the end of the crank in the exact same spot.
The only issue you might have is that one or more of the bosses in the engine cases that the pulse coil plate screws to might not be in the correct spot.  I ran into the issue that the Zephyr550/750 pulse coil bracket had one hole that did not line up with one of the kz750 engine case mounts.  I just elongated the one hole on the pulse coil bracket and it mounted up perfectly after that. 

Hope this helps. 

Hi Chris  I don't believe you will have any problems fitting the early 1980-83 mechanical advance ignition to the later engines . I plan on doing the opposite and upgrading the mechanical advance to the latter electronic version.
They all use the same crankshaft so the rotors will swap over. In 1984 Kawasaki changed the p/n for the crankcases and don't know what exactly changed but I am under the impression that the pulsing coil plates will swap over with out any modification. Hopefully one of the more knowledgeable members here will be able to confirm this for you.

Edit:: that was quick

Thanks for the responses. It sounds promising, so I've bought the engine and will see how it goes!