Following the tradition of gradual change, the 1977 Jeep Wagoneer kept the 401 cubic inch V-8, the 360 cubic inch V-8 and the 258 cubic inch I-6 that had been resting comfortably under the hood for a few years. The same 3 speed manual, 4 speed manual, and 3 speed automatic transmission options remained as well.  Of course the then innovative QuardraTrak 4WD system stuck around as well in the 1977 Jeep Wagoneer.  This part continuity from year to year that nearly all Jeep Wagoneers had is one of the reasons that they are so good for restoration and owning today, because parts from year to year can be swapped without much trouble.
The 1977 Jeep Wagoneer was not just a beast made for roaming through the jungle, carrying its hooting and hollering occupants anywhere they want to go.  There was some finesse and class built into the vehicle, in the form of the comforts available.  For example, cruise control, power steering, a powered rear window, and air conditioning, as well as an AM/FM radio with a cassette player.  Families could sit comfortable in the sizeable interior, confident that they were safe inside the sturdy metal walls.  And due to the convenience of restoration, families today can enjoy the interior, as well.