On the bottom of the lower control arm, head pointing down. No saying how much it will change ride height. This depends on many factors. Oh and it can radically effect your camber numbers.
Absolutely. These cars have a camber and caster curve that changes a lot in a short amount of travel. See the chart here:
That is with a 1973-76 A body disc brake knuckle but it isn't radically different from other knuckles used. The list shows "Dive" as compressing the suspension so negative dive is "rise", Note that caster goes negative just 3/4" above static ride height. Negative caster is horrible for steering feel and control. At 2 1/4" above stock height, you're at 3.3 degrees of negative caster. Going the other way, sitting 2 1/4" lower than stock ADDS caster by a huge amount. You're at almost 5 degrees of positive caster there. Caster is what makes the steering return to center after a turn and greatly adds stability.
No. If everyone just deferred to reading the manual, there would be no need for these forums.
Ride height adjustment is easy. NO need to consult a manual for tasks as simple as this.