1980 engine shaft swap

Hi I'm new here and I'm really happy that I found yous guys...
I have a 1980 kz1000 shaft that finely I had opportunity to get it, but I was told that, the engine needs to be rebuild it has really low compression and some valves issues.
I just want to buy a used engine for now and rebuild my original engine later, my question is, what engine years can I swap into my bike? ,
I found some information here and I read it, but still really confusing for me at least for now ...Thanks your patience in advance and your help!!!!

Shaft drive was an option in 79 and 80, not easy to find spare engine.