The drag pack ford offered on the older cars, like the 69-70 Mustangs was alot more than a Tach and small stuff.
The rear gear was usually kicked up to 4.10's or higher, there were also heavy duty Tranny and Oiler coolers, suspension pieces, traction bars, I believe also Sub Frames.
There werent any engine mods in ways of performance, but the chassis and durability of the cars and engines were tweaked heavily (well considering the time period).
Oh and they also added a tach.
