I'm going to go against the grain here and recommend building a 9". My Dart has a Strange S-60 and if I were doing it over I'd build a 9", better selection of gears and brakes, another plus is that used aluminum center sections can be found pretty cheap.
I'm not sure I buy the power loss deal, or at least it's very minimal. Go to any of the big heads up races and check their rear's, even Ma Mopar used a 9" under the DP cars and a power glide too. Blasphemy!!
