Now days you can buy them, back a while you had to cut and weld them approx 10 to 15 mm shorter, and had to heat them cherry red and quench in oil to put the strength back in.
I think Arizona z car sell a set in alloy that are 10 mm shorter, which quickens steering, rather than trying to remake the rack and pinion into a "quick rack" and they lower the control arms so that they angle a bit more downwards at the outboard ends. This helps to lessen bump steer effect, which they get when you lower a car.
Yes they are good for track work, and tight turns at slow speed will be a bit harder