Fox Body

quoted from wikipedia: :D

The Ford Fox platform is a rear wheel drive, unibody automobile architecture that Ford used for 15 years in the North American market. It was designed to be relatively lightweight and simple, in keeping with the general downsizing of Detroit designs in the late 1970s.

Its initial appearance was in the compact car class, when the Ford Fairmont and Mercury Zephyr appeared in 1978. Eventually, a wide range of Ford models in several market segments would be built off it, with multiple bodystyles and powertrains.

Vehicles using this platform:

1978-1983 Ford Fairmont
1978-1983 Mercury Zephyr
1979-1993 Ford Mustang (as stated above, actually up to 2004)
1979-1986 Mercury Capri
1980-1988 Ford Thunderbird
1980-1988 Mercury Cougar
1981-1982 Ford Granada
1982-1987 Lincoln Continental
1983-1986 Ford LTD
1983-1986 Mercury Marquis
1984-1992 Lincoln Mark VII
 
The term "Fox body" came from a directive that Lee Iacocca gave to the Ford engineering department in the early 70's. He wanted them to design a platform that could be used to build many cars (see Cenok's post above) and thereby greatly reduce the costs involved in manufacturing them. He told them to look at what Volkswagen was doing with the Fox. That platform was used to build the Fox, Rabbit (Golf), Dasher, Scirocco, 100LS and 5000. So Ford's internal designation for the project became the "Fox Platform", which has morphed into Fox body.

BTW, most everybody considers Fox body Mustangs to be 79 through 93. In 94 the Ford internal designation for the car became SN95 which ran through 98, then 99-04 are New Edge and 05+ are S197. You can nitpick all you want about shared parts, but the Ford designation changed in 94.
 
Technically the 79-93 is the Fox 3, and the 94-04 is the Fox 4 chassis.
I wonder whats Fox 1&2, could it be the LTD II/Continental the four door Fox chassis and the other is the long trunk like the Tbird and Mark VII...
 
Yeah all 94-04 are SN95's, but we stangers call the 94-98 body style the "SN95" and the 99-04 the "new edge" or the "new edge SN95".

I thought I remembered reading something in '99 that New Edge was a theme they were eventually going to incorporate into the rest of the line up, they also called the Focus "NE". Now all Fords cars are "edged".

When the "fox body" came out in 1979 it was a slippery shape, areodynamics at its best, now its the broadside of a barn door by todays standards.
 
Yeah, nothing really changed from 1979-2004. Almost everything is still the same. I am putting a complete 2001 drivetrain and dash in my 1981. Most of everything fits exactly the same.