I don't know. From the diagrams at Partzilla the 1100 uses a larger rotor bolt >> M12x40. while the 750-4 is M10x40. So with the larger bolt I would assume the rotor is different, possibly larger to fit onto a beefier crankshaft. ???
The cross-reference at Partzilla for the Spectre 1100 shows that a number of models used the same alternator rotor, including the KZ1000P police models thru at least 2001. The later police rotor has a different part number, but it may be useable as well.