I have a 1980 F100 that I would like to lower 3" in the front and 4" in the rear. I see lots of info on the older models but I can not find anything about the 1980 models.

Questions:
(1) Has anyone done it?
(2) Can the rear axle be lowered by changing the spring shackles or do you have to flip the axle?
(3) I see some ads for drop I-Beams for other years, but I do not see any for the 1980 series. Does anyone know of a source?
(4) I understand the later years (1982 up) incorporated ball joints which had some camber adjustment. Is it possible to swap in these axles to the 1980?

Thanks in advance for your responses.

Jerry T