The air-cooled torque converter (and transmission) is probably hard enough to get internal parts for already.
The chances of finding 'performance' parts may be like that snowball in hell...
Ford upgraded the transmissions and changed to a fluid cooler located in the lower part of the radiator in mid '56. For the trouble & price of a transmission rebuild or swap to the '56/'57 style trans you might consider a newer AOD instead.
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