I'm asking for a friend who's using a 12 Bolt Rear. He just tore up his Eaton 3 series unit at Englishtown Raceway when it hooked hard. Its a street/strip 3740 lb car. It has a procharged 505, TH400, 3.55 gear and uses a 29" MT Drag Radial and leaves off idle. It has 871 RWHP with 940 TQ. His best time to date has been a 9.89. He was thinking of going to a Detroit Locker but will it hold up? Also a gear change to a 3.73. What suggestions does everyone have?