More torsion bar questions...

Hey there, 1st post, loooongtime lurker. Im putting together a different Mopar combo, and wanted some suggestions.

Im putting together a 73 Dart Sport with an inline turbo 4 cylinder, all stock pick-up points on the suspension. Most drag front suspension setups for A bodies are based around a 440 (620lbs ish) or a 360 (510lbs ish), in addition to a full sized radiator. My motor weighs around 300lbs, plus a half radiator, so there will be alot less weight off the front end. My guess is .810 torsion bars will be too stiff, so what do you guys think in terms of torsion bars and/or front end mods that would help storing up and transfering that weight and energy? Thanks in advance...