Lift / Slapper bars on my Early Dart Dragcar

You can try them, but if they aren't long enough to contact the front spring eye they are just useless weight. IMO the best suspension going for A bodies are SS springs. Looks to me like your Dart is launching pretty good. If it ain't broke, don't fix it.
They reach to the spring eye (i mocked them in place ot check).I agree with the Super Stock springs being great ,but my car doesnt need alot of help anyway .I mainly need something to limit how far the rearend can rotate so i can use the transbrake ,and not damage the springs,or throw the pinion angle to far out of wack.The 8 3/4 in my car came ,from a pickup ,so i cant use a bolt on pinon snubber on the third member (it doesnt have the holes for it)...