1962 Valiant Suspension/Brake Swap Options with other A-bodies

The front spring eye bolt is a smaller size than later "A" bodies on the '60 -'62 cars. I do not know what specific year it was increased. It was easy enough to redrill the '62 front leaf spring mounting bracket to accept the larger bolt. I recently upgraded my '62 driver with a pair of '74 V8 "A" body rear leaf springs. The only negative for me was cosmetic, it raised the rear of the car 1.5" - 2". I also can't say with any certainty if this increase in ride height is due to a different arc as manufactured or just the difference between the tired 4 leaf '62 springs and the 5 leaf '74 springs which were also used. For reference, hypo cars typically have six leaf rear springs. In addition individual leaf thickness is greater (in both 5 & 6 leaf later year springs that I measured) than my '62 springs. I strongly believe it is all in the arc based on them side by side on the ground. Currently have about 10K miles on new springs with no issues other than the cosmetic one mentioned above.