Over the years, there have been many articles done on resetting the street Pantera suspension for radial tires, not for racing. They are ALL available in the POCA Archives. Use at your own discretion! A few highlights:
* 2.5-2.7 degrees is the max caster one can get from a stock front suspension. Offset upper a-arm bushings will increase it to about 4.2-4.5 degrees. Milling 0.100" off one side of the upper ball joint holders will further increase that to about 5 degrees. If you add power steering, also adding offset bushings in the lower a-arms (along with the uppers) will give 7+ degrees. Custom shims allow trimming to your preferences. No need to cut & weld anything.
* UPPER offset bushings should be installed to push the spindle top toward the cabin, while offset LOWER bushings pull the spindle bottom towards the front bumper. The effect is the same: tilting the spindle for better self-centering and more steering stability. Poly bushings only; rubber bushings are not made in offset configurations because being flexible, they are too imprecise.
* '70s Corvettes use 7 degrees on far larger front tires but they also have stock power steering. My little wife could tolerate 4.5 degrees of caster in our street Pantera with only a bit of puffing and grunting when parking. Above 25 mph one does not notice the steering effort increase from increased caster. She seldom went slow....
* Stock Panteras mid-'72-up got two 5/16" thick factory bump-steer shims between the rack mounts and the chassis. That fixes bump steering and is about the only mistake I've found with Dallara's design (taken from his '69 DeTomaso F-2 open-wheel race car). Lowering the car by any means makes bump-steer worse unless you readjust everything.
* 7" x 15" Campys have nearly 1" of positive front tire-scrub while 8" x 15" Campys have zero. So adding wider 8" Campys in front (with appropriately wider tires) actually makes steering easier & improves front tire life. Check this carefully with all aftermarket wheels.
* Old-school alignment of a Pantera rear suspension is done by backing the car onto an alignment rack and reversing the readings. At least that's the way Bear Alignment used to do it in the '70s. Due to the usual rear subframe collapse (fixed with a properly designed adjustable rear camber bar), the avg. Pantera has about 2 degrees of rear camber which cannot normally be adjusted out. Adjustable upper rear a-arms fix this but then reduce max rear tire sizes.
* Be careful in using stock alignment settings AND driving the Pantera anywhere near its capabilities. The stock chassis is set up slightly nose-HIGH (probably due to DOT bumper and headlight height requirements). Without a front spoiler, the nose will begin to lift above 110 mph. Raking the chassis about 2 degrees nose-LOW helps high speed stability.
* Changing components like steering rod lengths without rechecking everything often reduces or even reverses Ackermann-toe settings. This then affects low speed driveability. One really needs to know what they're doing in changing Pantera alignments due to 'unforseen results'!