The factory alternator is huge bothin physical size and capacity. I think it's about 120Amps which is great if you have a huge sound system, electric windows, sunroof, kighting everywhere and all the accessories and junk a regular car has or could hope to have.
I picked up a small alternator from a Japanese import wrecker for about $55. It still delivers 80Amps but is tiny compared to the original unit. 80Amps is overkill for a Cobra with is refreshing lack of electrical creature comforts. Especially when you think that not long ago most cars only had 55Amp alternators.
The bracketry wasn't hard to fabricate and I also added my own tensioner setup. If you used the factory tensioner the bracket would be even easier.
The only tricky part was the pulley which I turned on the lathe.
Cheers