Can 66 'A' brakes be upgraded to the "improved" type?

[YankeeClipper]

According to the 337 history document from Cessna Pilots, the 67 (or B model) had "improved" brakes. According to various sources of 337 performance specifications (e.g. Bill's), that model reflects this with a notably shorter landing distance. Since I'm interested in short field performance, I wondered if the A (or the original unlettered model) can be upgraded to the later type brake, practically.