489 vs 742

The 742 is in the car now, has Richmond gears, strange spool and axles. The 489 has Richmond gears and rebuilt posi. Reason I am asking is I am thinking of adding a billet yoke, caps and was wondering if the 742 would be worth adding to or build the 489. BigBlockMopar asked if I am making enough power to break one? I hope to :D I am shooting for 1000 hp with the new hemi and some boost.