8.75 Axle - 741 / 742 / 489

Mopar used the 741 in lighter weight lower HP applications and 742's and 489's were reserved for heavier higher HP cars. Like Rob said the 741 is plenty strong unless your hooking hard and racing a lot. But if the 742 you found is the gear ratio you want might as well go for it and add a sure grip. Either sure grip is a bolt right in. Just measure the R&P backlash before you disassemble it and when you install the sure grip set it back to where it was.