10SI or 12SI?

According to MAD electrical, a 10SI looks like:



and a 12SI looks like:





I'm rewiring my '69 CJ5 so I figured I'd upgrade the alternator.

From Kragen/O'Reilly, a 63 amp 10SI alternator is $34.99 (part #01-0039X).

But check out the picture on the website:





Looks like as 12SI, doesn't it?



I figured they had the wrong picture on the website. I went ahead and ordered the 01-0039X, this evening, I stopped by and picked up the alternator. The alternator I picked up actually looks like a 12SI, it's got the nylon enclosed fan.
It looks just like the picture in their website, and matches the picture of the 12SI on the mad electrical website.

So, is this really a 10SI?, or a great deal ($34.99) on a 64 amp 12SI?

 

I used the 12 SI becuase of the higher amp output. Works great and I didn't have to modify anything. Mine was around 90 bucks.

 

What model car should I order one for to get a 100 amp 12SI at the FLAPS?

 

All the info is at the Mad electric site. Check it out....lots of good info on there.

 

Good eye Patrick. The Kragen/O'reilly picture looks like a 12SI fan, but a 10 SI case (it's ribbed). I didn't notice that difference at first.

Here is a picture if my alternator:



It appears to have the 12si alternator housing (no ribs).

 

Check out this link:

http://www.madelectrical.com/electricaltech/delcoremy.shtml

 

I took a look at the documentation, this document also came with it:



It's hard to make out, but it says: