LCA bump stop clearance?
Years ago on my Barracuda I would shave down the rubber a 1/2" to get the ride height lower. It worked but the ride suffered a lot.
Best solution to go lower is buy new dropped spindles but you have to have the 73 and later upper arms and 73 upper/lower ball joints I think.
Here is some
http://www.magnumforceracing.com/store/detail.asp?ProductID=3939