I am currently working on the conversion which requires; changing the bell housing, changing the input gear on the NP231 to a 23 spline, machining a custom pilot bearing, replacing or modifying the driveshafts, modifying the trans mounting, changing to a 10 spline clutch, changing the shifter linkage, and changing to an external slave cyl depending the year. Time and cost?
After a call to AA they quoted $450 for adapter, $190 for 23 spline NP231 input gear, $24 for new shifter linkage, total $600-$650 may vary slightly depending on year Jeep you have.