Having experience with several lightning hits, you can expect what insurance adjustors term "latent damage" to cause units to drop dead for no apparent reason for up to a year after the initial strike. Most good insurance companies allow for and expect this and will replace future failed equipment with very little argument, or at least they used to! I'd definitely ask if that would still be the case after an ownership transfer.
Devices with semiconductors in them are the most likely candidates; AC units, fridges, nav equipment, transducers, microwaves, etc. You didn't mention if those Detroits were DDEC or mechanical, but the DDEC controls might be a problem.
If you like the boat AND it will have insurance coverage for this, it will be just a nuisance, and you will get newer, updated units when they fail which will make her even better!