Stroker and all,
I used the info on Mad's alternator pages (the Lester number), ordered a 12SI in the 90 amps range, and got just what I needed from a local alternator distributor. From my experience we can have confidence in the info on Mad's website.
The 12SI fits the same as the 10SI with the excpetion that the boss on the top of the alternator is tapped for a metric bolt, no big deal. I needed to move the alternator away from the heat from the headers and could not get there with the stock slotted tensioning bracket. So I got two 5/16" rod ends and a 4" long coupling nut (mcmaster carr catalog)and used them in place of the stock top bracket. I was able to use a longer v belt and effectively move the alternator away from the headers.
Thank you all again.
Ken

Last edited by El Viejo; 01/19/10 05:28 PM.