I just bought a 1998 mercury 40elpto and was wondering what the diff. was between the larger size hp with the same block ie. reads, programing so on. i guess what i am trying to ask is what would it take to up grade mine. i used to have a 97 50hp that was the exact same and when i bought it the guy said he had run it hot and had to send it to his buddy that ended up doing some extra work to juice it up. it was a tuff little motor and fast wish i never got rid of it
