The 3.23 ratio was used to get this rather large beast to where it would move. If you plan to put this third member in a big block car it is still a good choice for overall driving especially if you desire some performance from a post '71 smog motor. This ratio was standard on most 383, 400 and 440 equipped cars in the late '60's and early 70's. Some of the Imperials and other large Chryslers used the 2.76 or 2.93 for better fuel economy. In the smog era the emphasis on performance had largely gone away in favor of fuel economy.
Dave