Will it fit?

A while back I bought a 76 Z900 which proved too nice to part out. Not realising this would cause me some problems down the road, I sold it.
Now for the present day: I have an untitled '75 Z1 frame I'm building. The hard part is getting an engine. Not so much the engine itself as proving the provenance. Which I'll need to do in order to get a title. Now to my question. Will A set of ST cases fit if I build it up with parts from a Z1 engine? (I can get some titled parts including the cases locally).
 

Everything from a Z1 engine will fit the ST cases .
However the trans cover on the ST cases has a different bolt pattern to the Z1 and is also a bevel drive for the shaft so you will need a trans cover from a MK2 engine which shares the same cases.
There are other differences with the MK2/ST crank, cam sprockets and alternator but if you stick to just fitting all pre MK2/ST parts in the ST case with MK2 trans cover you won't have a problem.
 

Where do you live that titles engine parts?

The elephant in the room here is, do you intend to run a shaft drive on the Z1 frame or convert the ST engine to a chain drive? the Z1 frame is to narrow for the shaft drive swing arm and even if its wasnt the swing arm has pivots and not a through axle  like the Z1 frame has. I can show you pics if you want.

@TexasKZ: I live in the Netherlands. We had a bit of a problem with stolen Harley's. Use an aftermarket frame, get it registered and bingo, you're good to go. So now you need to be able to provide the proof of provenance. It's just another case of the few spoiling it for the many.

@ kzstreetfighter71 I was hoping to run it as a faux Z1 engine. But considering the rarity of mk II parts over here, to convert it to chaindrive, , that might be a dead end as well.

I tried a few breakers on the fleabay that had some engine cases for sale but thus far no luck getting them to cough up a frame number.
 

Iv done an ST to chain conversion, its not that hard, all you need is a gear set and a few small modifications but what will you do if you have an engine and frame, how do you makae that legal?

Here in the States the title and registration go with the frame number. The engine number isn’t considered. That why nobody here will give up a frame number. Am I understanding correctly that in you situation the engine number is used to prove ownership? And you have an ST engine that you have paperwork for, thus attempting to put it into the frame. 

I just show up with the frame and engine. They check it over and issue a registration. After that it's never even checked again. So as soon as I have it registered I can put in any engine I wish. So I was hoping to get to that point with the ST engine ( I haven't got it yet. Just saw it for sale)

ST engine is easy to convert to chain.
You mainly need the output shaft from any Z9/Z1000 ( to put the ST gears on) a MK2 trans cover and move the gear selector shaft to the other location boss.
Done it a few times myself.
If you just need the ST motor for registration then just use it for that then either convert it or sell it and get another engine.
ST motor will bolt straight in the 900 frame for registration purposes if that's all that's needed.

Ahh, something like that here, you have to have the bike built though and running,rollers wont cut it, so you have to put all the money in first. Then a letter of authenticity from the Japanese vintage club, then to the lets call  it the DMV... quick safety check and its registered. As fir the ST there are parts out there and there were other bike that have the same engine, 1980 LTD and the Z1 classic.

It's give and take with the bureaucrats. We don't have to have it running. I can show up with an empty husk and they'll issue a registration. So I might try it with teh ST cases. They're dirt cheap anyhow. If it doesn't work out I can build the ST up. Might do that anyhow if the Z1 get's registered. You can never have too many bikes.

i dont know... i have 20 and there is little or no room for anything else.. if you are up for a road trip there is a lot for sale in Germany.