I own a 66 F100 and like it. Of course it's not stock. I have all the original parts but I did put a built 351W, C4 tranny, power steering lowered and drop beams.
The only thing I do not like about these trucks are the Twin I Beams. Twin I beams are fine for hauling and to use as a truck but if you want a nice street truck and lowered they are a pain to lower and cost a lot. BUT.... There is a fix for this and it's quite easy and nice (takes a lot of weight off the front too). Find an 03 and up Crown Vic and use the crossmember from it. These are aluminum which are MUCH MUCH lighter than the whole Twin I beam, they are power rack and pinion steering and the best thing... They bolt RIGHT UP to the stock frame on the 60's F100's. Doing this swap without drop springs or anything will lower the truck about 5 inches.
You can get these crossmembers from a junk yard for anywhere from 200-400 bucks and that includes EVERYTHING on the front of the frame.
Slick60s.org
Check that site out.