Im wondering what year in the 90s the 35-50hp mercury changed the design of their lower unit? Ive got a jet foot that should fit any 35-50hp between the years of 1965 and somewhere around 1997. The guys at outboardjets.com didn't know what year they changed and, strangely, neither do the guys at the mercury service/parts department. I've got an E series Jet foot serial number 49681. I just want to be sure that my foot will fit before I purchase an outboard. Also, anyone happen to know if the Tracker has the same lower unit design?