A904(late) and A998/999 transmission

Actually, all the OEM 727's and 904's have a 2.45 low, not 2.54.

JW Transmissions in Rockledge, FL does mine. But I'm not sure what specific parts need to be swapped over. I do know the gear set comes as an assembly that has to be swapped as a "set". Not sure of any additional parts or work needed. But a competent trans shop/person, especially performance related and/or specializing in Mopars, should know.

The low gear set will help the most if you have a heavy, mildly powered and/or low numerically geared rear end vehicle. It can help give more accelleration from a stop without sacrificing fuel mileage in high gear.