The rotor will likely draw too much current for the field circuit of any factory wiring. Although in theory the 'on' time will be shorter, assuming the regulator can cycle that fast.
AFAIK there never was a 100 amp alternator option for any of these cars. I vaguely recall seeing a listing for Leece -Neville alternators for ambulances but don't recall whether that was even for a Crhysler product.
Bewy and Townsend both touch on the likely thinking. Its worth the savings in copper to make 1000s of cars with alternators that have smaller diameter wire or less windings in the rotors and stators. But when replacements are needed, the savings in production and inventory negate the savings in copper and/or the extra cost is covered by the customer.
