'73 Dart Sport 340 H Code leaf spring replacement recommendation

Exploring my options. I have a deep 727?trans pan from Mancini that hit bottom once stepping very slow from my driveway to street cause it’s a low curb. Not a normal driveway graidient low angle. I have a new Mopat Performance pan for the spring to but on that’s not as deep as the Mancini one.

Just that that there virtually no arch to the springs and they appear to be original that time replace to restore the height.

The 15” rear rim and new tires is an option.

Thanks!
Eric