Super Stocks Springs have i reached the limit?

I ran S/S springs for many years on my Dart it actually ran its best 60 ft and E.T. on them : 10.40 with a 1.40 60 ft. I switched to Cal Tracs , their mono leaf springs and rear ( Rancho 9 way adjustable ) shocks awhile ago . My 60 fts became more consistent . I tried the Calvert adjustable front shocks and for some reason my car didn't like them as my 60 ft consistency dropped , I went back to my ancient Koni SPA 1 shocks and they have been fine. Although my car is now slowed down to run 11.50s it is very consistent in 60 ft. recently on 6 runs it was 1.59 in 60 ft ( deep staged ) so 1.49 shallow in both lanes . I only leave at 2,000 rpm ( foot braking ) and run a 4.30 gear with a Hoosier drag radial at 18 psi .