1979 crossflow power pack test?

[Kracker Jack]

How do you test power pack failure? I have a 1979 135 hp rude that I took off this v20 that I have compression tested 2 weeks ago and very very very surprisingly has awesome compression ranging around 129 to 130 on all cylinders. I drained lower unit oil and it came out clear and clean. But I have no spark on any of the 4 cylinders which tells me the power pack is bad how do I test for this? and would one of the twin power packs off a 200 seahorse of the same era work on a single power pack 135hp thanks fellas!!!! I have 2 135's one that has been family owned since new that is gonna go on my v20 and a 135 that came with this v20 that I never expected in a million to pass the compression test I did a couple weeks ago and this motor would be a great bonus if I can just replace the power pack to get spark back.