I bought a 1970 Mustang at a auction last January and it was missing half of the suspension. I needed to get the car to a rolling chassis status and had a 77 Granada parts car. To get the 70 Mustang up and moving I used the control valve, lower control arms, the front and rear springs off the Granada. Everything was a bolt in except for the front springs, which I had to cut down a coil. The control valve off the 77 Granada bolted in but the hoses wouldn't work, as stated above. This was done to a 70 Mustang but I would suspect that the 66 Mustang you have isn't much different.
Here is a link to the information on the suspension work I did on the 70 Mustang.
1970 Mustang Suspension Question