There should be a locating pin for the pad. And when I say pin, it's actually only an inch or so long.
Something kinda like the pic here:
http://www.summitracing.com/parts/ptp-7-1708
If I can ever get done with $#!7 projects inside the house, I plan on installing my Nova 8.5 into my 67 FB. I bought new spring pads and shackle bushing kit from Energy Suspension. This weekend, hopefully!