Well, to help with your phallic stomping, let me give some dates and general appearance nicknames to our beloved Ferds;
1. Start a little early. The 1966 was a unique model. Not quite a bumpside yet, but a very attractive grill in the upper trim levels, and fairly rare here. Id consider a 4 x 4 custom cab variety a bucket list find.
2. 1967 through 1972.
Same basic body style with slightly different grille and emblem changes.
They call those "bump sides", due to the common convex swell in the upper body panel. Fine vehicles, but all have the fuel tank behind the drivers seat.
3. 1973 through 1979. My absolute favorite years(maybe because I was "hatched" in 1973).
These have become known as the "dentside" years, due to the common "dent" or concave arch in the upper body line. They also wisely decided to relocate the fuel tank or tanks to the chassis, and therefore free up some cargo space behind the seat(oh, and not incinerate the driver and passengers)

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They also made a lot of changes in the outer and inner appearance through those years.
Biggest for me was the grille design.
1973-74 had a simple, round headlight rim cast into the grille, with horizontal slats. Any emblems or upfit badges were put either on the hood, or on the fenders.
1975 through 1977(and some 1978) added a square perimeter to the headlight bezel with slightly diffent trim accents each year.
Major design change in the grille happenned mid-year 1978. There were cab and interior changes, but the grille was dramatically changed for the mid-year model, but they kept the round headlights.
1979 was a standalone model with the mid-year mods, and finally went to square headlamps.
1980 brought about a complete design change from the ground up, and ushered in the "Bullnose" body and the "stupid arse" TTB front axle on the "supposed" 4 x 4 models.
Before that, all 4 x 4 pickups, 1/2 ton up, came with a straight front axle.