Well, the alternator turned out to be a "poor" experience at this point. It arrived today. I wasn't SUPPOSED to have to pay taxes or brokerage fees but it came with a bill for $41.56 from UPS. It was shipped direct from the vendor rather than CarParts/J.C. Whitney so I'll see what they'll do about it.
Then, I unpacked it and... it's not chromed. Just a plain bead blasted surface.
I start digging into it, and the label has the correct part number from their site. Should be an 80 Amp Chromed unit. Then I notice the label is on top of another label. So I use a hair dryer to warm them up and start peeling off the layers. There are THREE labels on it. Long story short, instead of part number A7127SE6CH(6 volt, 80 Amp, Chrome), the part numbers under the top one are A7127SE6.
Looked on the carparts web page and that part number is for a 6 volt 60 amp alternator with a plain housing. So it looks like the vendor is pulling a fast one on JC Whitney/carparts and relabeling parts to give the impression they are something they're not. Not Whitney's fault but I expect them to make good on both the part and the broker fees I shouldn't have had to pay.
And all of that was to say that your duct, just might not have the right part number on it.