hellwig swaybar install

NEway, if the spring rates, damping and swaybars are well matched ft/rr, assuming basic susp geometry is decent, you should get a fairly well balanced vehicle; especially since the A-body with either the /6 or smallblock has a very good front to rear weight bias.
What's well balanced?

'64 GT Dart, 273/904, manual steering and brakes with AC and about 1/3 tank of gas.
Without me
FL:932 FR:960
RL:698 RR:672

1892 front / 1370 rear

3262 total

58% front 42% rear

With me
FL:986 FR:976
RL:732 RR:688

1962 front / 1482 rear

3382 total

58% front 42% rear