need new leaf springs

i thought i had a thread for this already but i cant seem to find it but i have finally got my car done and been driving and i noticed my right rear kept bottoming out and it sits lower than the left so i rolled her into the bay and looked at what shes got going on and my right spring is loosing its arch. I wanted new springs anyway so I was wondering what everybody here uses on their darts, not looking for super expensive but I do want some good ones, I know that doesn't go together but you know what I mean. I am after something a little more arched than stock because I want more stance than what i have. I have a 1969 dodge dart with a 7.25 rear-end and air shocks in the rear, I don't mind moving spring mounts and the end goal for this build is a street-strip car so its performance oriented. thanks in advance guys