I have been using 2-5/8 AFCO springs where the 2-1/2 TCI All American brand were originally installed. They fit well. I'm also using 10" with a 2" special ($$$)spacers on the rear where there were 12" tall springs.
Have been used for over two years. My reasoning - only .062" on the radius - first bought a pair for the front, tried them for size, looked fine so bought the rears along with spacers and now have several thousand miles on them. Here's a photo of one just before installation and as far as fitment with the originals - looks virtually identical