1965 vs 1973 7.25” small bolt pattern axle

Are there any differences between a 1965 SBP 7.25” 9” brake axle and a 1973 SBP 9” brake 7.25” axle?
Length, flange thickness, spline count, shaft diameter, bearing, mounting plate, etc?

I have a 65 valiant with a 73 duster rear end. I bought replacement rear axles with bearings and mounting plates attached that were for the 65 rear. They are drilled for both SBP and BBP.I would like to put them in the 73 rear if they fit?

Thanks