On my 70 MAch 1 I installed Global West Tubular Upper upper and lower control arms and their adjustable strut rods. Also used their Eccentric Loc-Outs. The kit provided a 1" drop steel template for drilling the lower upper control arm pivot holes. I installed Global West Coil Springs (#: s-27), which are stock height performance street with 640 pounds per inch. I welded in some of the BOSS track Mods... the Shock Tower reinforcements plates and the crossmember lower control arm eccentric anchor plates (I chose to use Global West Eccentric Loc-Outs instead). I also converted my manual steering to a CPP GM style power steering setup and swapped my front spindles and drum brakes to stronger Granada front spindles, and calipers with slotted/drilled rotors. I just finished the restoration, and have had limited opportunity to drive the car, but so far so good.
Here is the Global West Suspension product description...
https://www.globalwest.net/mustang-1967-1968-1969-1970-tubular-arms-strut-rods-front-suspension-global-west.html
1967-1973 Mustang Plus 3 Upper Control Arms # MNR-733 (Sold as a Pair)Global West has engineered an upgraded upper control arm for 1967, 1968, 1969, 1970, 1971, 1972, and 1973 Mustangs; the arm provides additional positive caster by moving the upper ball joint back towards the rear of the car.
This particular kit is used for street and handling applications. (Global West also manufactures a control arm for drag racing / street.)
The new Plus 3 Mustang arms are shipped assembled with billet cross shafts, Del-a-lum bushings and ball joints. The a-arms are black powder coated and the cross shafts are blue zinc (silver). Global West manufactures this product in its own facility here in San Bernardino CA.
Tech Information: Caster
With upgraded suspension and present tire technology, caster plays an important part for proper handling of the car. Caster does the following: provides straight line stability, has a self centering action on the front suspension, improves initial turn in during cornering and also resists pulling (right hand drift) caused by road crown.
The Alignment Adjustment and Limitation:
Caster on 1967-73 Mustangs is adjusted by moving the lower control arm forward via the strut rod. The strut rod is threaded at one end where the rubber bushings reside. By loosening and tightening the jam nuts you can pull the lower arm forward gaining more caster.
This was not an option on 1967-1973 Mustangs. The real limitation on how much caster you can get is mainly based on the rim and tire combination you are planning on running. The larger sizes limit how far you can move the lower arm forward because the tire runs into the lower portion of the front fender when the wheel is turned.
If this occurs, you will have to reduce caster, which is not the best answer. Now with Global West Plus 3 upper arms you will be able to get the caster you need!