At fz750.net forum there’s some talk about it. It’s said only the 1st generation 135 hp FZR 1000 engine would fit, but I’ve read from smwhr the 2nd gen. 145 hp engine should bolt in just as fine too.
..and I know u didn’t ask for this info, thought to add it to maybe get some comments about this EXUP engine in an FZ frame..