What should i change to get into high 11's?

With your Horse Power, frame connectors aren't going to do anything. Look again at my wifes 72 Dart (above picture), no frame connectors, stock worn out rear springs SNUBBER and 3 way Comp. eng.adjustable shocks only (stock shocks in the front) Stock V8 torsion bars etc.No roll bar,full wieght of 3250 lbs.....it's all in the converter, & gears, mostly gears bud.Harder leave quicker ET. (if you got traction).
And by the way SNUBBER yes, yes, and yes, look at my mild BB Valiant with only SS springs, 3 way adj shocks, and adjustable SNUBBER.SB V8 torsion bars, stock front shocks.3300 lbs with my big butt in it.