[66_Cat_Jon]

I've also asked this in the "61-66 Big Car" section but maybe there's someone here that knows. Many years ago I put a big car posi rear under my 66 Catalina. I was told the housing was from a 1968. I'm riding on 66 Full Size springs and I've just ignored that the bottom of the spring is much larger than the circular perch. Now I'm wondering if I should use 1968 springs to match the bottom spring perches. Does anyone know if 1968 Full Size springs will have the appropriate spring rate, ride height, and top diameter to work in a 1966 Catalina?