I agree with Chief on checking easy stuff first. Welded the bracket? Is it located properly? The Z-bar should be nowhere near the brake booster.

As for the pedal return I grew tired of that too. I finally added a third spring that goes from the clutch pedal to the back of the dash. That pulls the pedal all the way up no problem. So I have one spring pulling the clutch fork forward, one spring between the fork and Z-bar keeping the lower rod tight, and one spring pulling the pedal back to the dash. I use the rubber stop on both pedals and they are even.

Relocating the rod holes in the Z-bar can change the geometry drastically. The last time I rebuilt my manual trans, I reused the pressure plate, flywheel, throwout bearing, clutchfork, everything but the disc. I put a brand new disc in. That caused all sorts of problems. I could not have pedal free play and still get full disengagement. I needed more travel from the lower rod. I am using the Speed Pro spherical rod end upper and lower adjustable rod set. I still could not adjust things properly. I had to drill another hole for the upper rod in the Z-bar about an inch lower than the stock hole. That way I got a lot more lower rod travel. It changed the angle of the upper rod and I had to relocate the firewall hole. Overall I prefer this set up and I don't feel any extra pedal effort.