The 250's are great motors and similar in power and weight but they are not designed for cat hulls. The midsection,especially the motor mounts and the lower unit are not setup for the intense driving conditions of a cat. I can promise you within no time you would be replacing the exhaust adapter plate which of course holds your motor mounts. I know they have that new 250x and maybe it is more study in the midsection and you might be able to buy a speedmater lower unit as an option but you will spend money to make those 250's adaptable and almost certain they will break. good luck in any case and youll love your new 28. 2.5's are definitely choice. safe boating.