Re: '77 F150 Suspension
If your truck is 2wd, you can also get lowering spindles for the fronts (assuming they make them for your truck) rather than messing with the stock geometry up front. The spindle is held in place by the upper and lower ball joints and can be easily changed to a "drop" type spindle that essentially moves the center of the wheel up.....which in turn lowers the vehicle. The good thing is that the stock steering geometry, springs, shocks, etc. are unaffected.
The back is a simple job with either a spring or shackle kit but may require new shocks, depending on how much you drop it.
That's about all the advice I can offer on that. Not sure on whether or not the suspension parts from the F100 will work on your F150....
1992 Ford Bronco
E4OD- B&M Stage 2 shift kit
Full 3" stainless Bassani Exhaust
32" BFG's/stock suspension
"No replacement for displacement."
"Our lugnuts require more torque than most Honda's produce!"