In my article "Statistics of Word Neighbours" in the Nov 2997 Word Ways, I showed that theoretical expectations matched actuality quite well for heterograms, words of a given length which had all letters different (Graph 2 in that article). In "Snakes and Ladders" I attempted to make ladders between heterograms which were also words when reversed. This article gives Fuller results of my investigation into reversible heterograms. The lists can act as a crib for people constructing palindromic phrases!
Word Ways: Vol. 31
, Article 5.
Available at: http://digitalcommons.butler.edu/wordways/vol31/iss4/5