I have a new set of LCAs with ball joints from a B series van that I bought from rockauto.com and they lower the shock bottom mount about 2" (the depth of the spring pocket) and if you use them you should not have an issue of reduced effectivenes due to angularity. I may cut a half coil too...I need to get that body down out of the wind if I want to develope some speed in the quarter.

'68 to 70 B-Body shocks are a good place to start.