I wouldn't bother with those truck helper springs. Looks unnecessary complicated. I would just add another leaf in the springpackages.

Just look for 2 similar sized leafs that fit nicely in between the other leafs. You can grind too long extra leaf shorter on the ends so the center pin stays in the correct location.

I added leafs in the springpacks on my own Dart. I'm upto 7 leafs per side now, but I'm also carrying two propane tanks in the trunk.

QA1 adjustable shocks control the rear and adjustable Hotchkis shocks are controlling the front of the car along with a Hellwig front swaybar.