Just had front coils and shocks replaced on 1970. I have a 1" height difference from passenger side being higher than driver side. When looking at car head on. I measured from top of wheel well to floor on both sides.
Are you sure the new springs are both the same length and stiffness? Was there a spacer left in one side?
You should also look at any height differences due to the rear springs. The left rear, if sits too low, can affect the right front.