If I remember, 54.5 is the length. You can try Ebay for the specs for the Nova years. I remember seeing a few there with years listed. My 12 bolt was from a 67 Camaro with mono perches. I would rather have a multi leaf 12 bolt under the 67 but unsure if it will interfere with the staggered 68 shocks.
What year Bird?
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.