I have QA1 lower control arms.
I suspect that's the issue. On stock lowers there are stops that contact the radiused lumps on the lower ball joint limiting travel. I'm thinking that is not there on the QA1 arms.
This pictures shows what I'm trying to describe.
A-Body LCA on the left E,B-Body on the right When I used A-Body LCA's I had the opposite problem ( not enough travel) as the a-body ball joint stop area protrudes out instead of in like E-Body LCA's I had to mill some of that nubbie off the lower ball joint to get the travel back.
You might need to weld on tabs that contact this ball/"nubbie" area to limit travel?