A couple of good suggestions with my thoughts, still looking for a flash of brilliance. Don't hesitate to suggest something obvious, wouldn't be the first time I missed something easy.
Hi,
I put a 69 ply RR suregrip rear under my 54 Desoto station wagon and used the 56 Shock mount pads and 56 shocks . I had to move the spring perches on the housing a little. Couldn't you use yours as well? Just a thought.
John
I would like to have used the orginals but the lower mount is an intergral part of the spring pad, they just kicked it up at the back and fastened a shock mount style bolt to it. So, it must be a little different than yours.