Update...so I grabbed the 741/3.23 case, guy’s car days were behind him so he threw in an open 489 case with 2.76 gears. Just what I need, more parts laying around! I’ve rebuilt the 489 case clutch suregrip in the Dart so looking forward to taking a run at this one. Found a pretty good post https://www.forabodiesonly.com/mopar/ams/how-to-recondition-a-sure-grip-cone.28/ that should help.