That'll work. If you feel for the resistance on the lower control arm bolts, you can figure out when there is almost no pressure on that pivot point. Once those are disconnected, the arm lowers down fairly straight from then on. A bit beyond that point, things will start to bind up on you.
When you put things back, don't tighten the LCA bolts down until the weight of the vehicle with engine is on the tires. Otherwise the rubber bushing will be under stress. If you have delrin bushings, this doesn't matter.
A washer large enough for under the a-arm can be hard to find. An old lawnmower blade will work fine for that.
