Slingshot engine in slabside

[Dizzymole]

Hi, searched the forums but can’t find the answers. 
I have a 750 Slabby  but no engine, would a 750 slingshot motor fit straight in and what stumbling block might I encounter? Also, what would you expect the compression to be on a half decent slingshot motor? 

[Upshotknothole]

Any oil cooled engine will bolt right in. I think the compression should be up around 150, but that's just a guess off the top of my head. Check the archives, plenty of info in there on engine swaps.