Super Stock Springs and 60' foots

I 60ft low 1.60's in a 3550 lbs 67 belvedere, using ss springs and a snubber. all on a 27 in tire. 4.30 gears with a 440. I UNCLAMPED the REAR clamp from each spring, and picked up .08 on average. I also use the CE shocks all around, and slant 6 torsion bars.