Closest to a 3.55 ratio for that rear will be a 3.42, Looks like the average price for that gearset (R&P only, no install kit) is right around $200, new. Figure about another $100 for the install kit. That gear would require a 3 series carrier (3.08-3.42), which would add around another $370-$700, depending on whether it was an open diff or Positrac.
