Adding ABS (Anti-Lock Brake System)
Anti-lock brakes can greatly improve your braking distance when one (or more) wheels loses traction. This is because if one wheel locks up or loses traction, the ABS can automatically modulate the braking to the wheel that is slipping. It does this by rapidly pumping the brake on that wheel alone (or rear wheels in a pair) faster than any human ever could. This will also prevent a braking-induced skid in adverse weather conditions or on a bad road by maintaining traction while braking. On dry pavement, it will keep the brakes from completely locking up which will reduce stopping distance.
The ABS VI system is GM's most inexpensive ABS system. It uses the same vacuum power booster and master cylinder as a non-ABS car, but adds a modulator assembly and ABS computer. To add ABS to a non-ABS car would involve adding a modulator assembly and the ABS computer (called the EBCM - Electronic Brake Control Module). You would also have to add wheel speed sensors to each wheel. On the rear, that would involve replacing the rear hub/bearing assemblies. On the front, it would involve adding the pickup sensors and replacing the outer CV joints which has the sensor ring. It sounds rather complex, but surprisingly enough, the ABS VI wiring is less complex than that of a Clifford alarm system.