Hi to all, All the cars that have I changed from a spool or locker to a torque bias type differential have gone faster and the drivers have said it was easier to drive. I like the Eaton Detroit Tru/Track diff. it is a geared type like the high dollar Gleason Torsen diff. But unlike the Gleason the Tru/Track can have the break away torque set. I know cost is always a factor , but I do not like any geared diff. that uses aluminum cases. I know I'm an old school guy and believe drive feel is really important and if they can drive it, they will go faster. Hope this helps. Mike