yes, sort of. That is just the wiring kit,
which you would need if you bought a 3-wire 10si alternator, the kit would be worth it to properly wire it up. but you still need to buy an alternator, the biggest thing will be the mounting hardware to get it to mount on the engine and the alternator pulley lines up with the belt. maybe give that madelectrical site a call and ask them about mounting kits for a 10si onto a sbc to replace a generator.
you can buy a 1-wire 10si alternator in which case you would not need that wiring kit. But the 1-wire alternator is not as good as a 3-wire for a few reasons, all of which are explained real well at that madelectrical site.
here's a few links of just alternators from jegs, 1-wire & 3-wire
http://www.jegs.com/c/Switches-Batte...10685/10002/-1
-
http://www.jegs.com/p/JEGS/JEGS-1-Wi...50748/10002/-1
-
http://www.jegs.com/p/Proform/Offici...59723/10002/-1
-
http://www.jegs.com/p/Powermaster/Po...55506/10002/-1
quick google on 10si mounting bracket,
http://www.kansasselectproducts.com/...bracket/Detail
there's a bottom bracket that the alternator sits in, then a top bracket or arm that that lets you position the alternator to get the belt tight. the part on the 10si casing that sits in the bottom bracket is called the foot, and i think is 2" long, so the bracket has a 2" gap to accept that foot which the mounting bolt goes through. I think the 10si alternators have come with different foot sizings over the years so that would be one thing to make sure of before buying the alternator and bracket- make sure the alt. foot fits the bottom mounting bracket.
http://www.alternatorparts.com/Alter...brackets_1.htm http://www.jegs.com/c/Switches-Batte...10363/10002/-1
Converting from old generator to alt. 
