For completeness, I'm gonna add a few to your chart from my sources (though *I have not measured my '65 valiants axle!) But I think the measurements in your chart are not "flange to flange", mine are. But most importantly, this lists leaf cell spacing:
1963-1972 A-body : 7&1/4 : 53.2" flange to flange : 43.02" Leaf Center to Leaf Center : 10.09" center axle to center ujoint
1973-1976 A-body : 7&1/4 : 51.4" flange to flange : 43.02" Leaf Center to Leaf Center : 10.09" center axle to center ujoint
1973-1976 A-body : 8&1/4 : 51.4" flange to flange : 43.02" Leaf Center to Leaf Center : 11.69" center axle to center ujoint
Reference: Chyrsler Performance Upgrades, 1999, Frank Adkins ISBN 1-884089-40-2
Long story short, I need to look into this Maverick idea more... that might be a nice way to go...
