Portugal RSC2's and RSC3's

How were these uprated to 2,000 hp?

Never seen any mention of them being repowered with 12-251’s like some US RS3’s were rebuilt with, yet I’ve seen the 2,000 hp figure cited more than once through the years. Did they actually successfully squeeze 400-500 more horsepower out of their original 244’s?

See message 8618 on the World Diesel Locomotives yahoo group. It states that the Portugal RSC-2s and RSC-3s were reengined with MLW 251Cs in the early to mid 1970s.