Re: 1979 Trim and Tilt Replacement
The 79 version had a three wire motor which required a relay box with a solenoid mounted underneath the splashwell in the boat. In mid 81 they changed to a two wire motor which required a different box with two relays. By 1983 these boxes mounted on the top of the engine's exhaust cover, under the cowling. These later exhaust covers have special holes for mounting these electrical boxes. While I think many of the crossflow trim units are interchangeable between the clamp brackets, a newer unit will require some electrical reconfigurations.