What coil over/spring set up are you using? The plans call for 10'' coil over w/ ball joint ends, w/ 8'' 400lbs spring. If you chassis was built to speck... you`ll NEED coil overs with ball joint ends. Because, the coil over movement path, is not straight! Some guys use a poly bushing coil over, and move/make an upper coil over mounting bracket.
I`m using a 12'' QA1 coil over w/ a 10'' 500lbs Eibach springs. I reengineered the upper a-arm, ball joint bushing pitched 7* now I have full range of motion without any binding. Reengineered the coil over attach points, on the upper a-arm (pitched it towards the cockpit) and change the upper mount, for a straight path, eliminating the need for ball joint ends. Note: 10'' spring is difficult to get on, and installed.
My setup is not tested. So I don't know how much help I can give you?