some quick research and it appears that p/n 8M0064021 is the most current alternator for the 240efi sportjet. you can call Crowley marine and give them the make/model/year/serial number and they can tell you what the part number is and the cost.
Took every alt off..
Delco remy
5si/19020703
875285 are the numbers on it..
I googled the numbers, but it says out board engines!!
It's also a lot cheaper..
Why is this so difficult to look up?