Rear leaf spring Question 74 Dart

Have you looked into having your old springs re arched?

Most semi truck shops will do it for cheep.
Call aroumd to heavy truck equipment / repar shops and ask.

I had custom U bolts made at a truck repar shop here in Ca for dirt cheep. They also re arch springs. I know the shop i used is to far away for you but in Ohio i bet there is some place near you that works on heavy trucks?