jcp, not sure what motor you have, so you,need to go by model #, but this is the kit for my 94 150.
http://www.amazon.com/MERCURY-MARINE.../dp/B001HBUSK8
the merc part # is 46-96148A
also, like ferm says, if your going with new t-stats & water pump kit, i'd get the poppet valve kit also.
i change all of those once a year in mine.