We finished our research with the wavetrac, the crossfire wavetrac fits our new to us differential with the 3.90 gears.
this means that if you want a 3.90 limited slip diff, you can use the wave trac that was made for the crossfire.

By math the increase is equal to 70HP ,,, 60 mph at 2600 rpm and 80 at 3400rpm this is with stock size tires
this means most srt 6 crossfires with some mods will run in the 11's with drag radials ofcourse. jim