<VV> Engine building - Alternator

[Les]

Hi all,

I understand that if we are using the external regulator that we can get 
a rebuild '70ish Chevy alternator locally and swap the innards and fan 
to the Corvair front housing.

The note I have is: "Use '70 Nova 6cyl to get 37 amp, but if you get '70 
Nova V8 with A/C you get 63 amp."

However, it's a bit confusing to me whether the REAR housing for Chev is 
correct - there is some discussion about the bolt hole for the rear 
brace not being present on Chev alternator but available on 
Buick/Olds/Pontiac.

So should I be asking for an alternator for a '70 Pontiac instead? Any 
particular one?

Thanks,
Les