Another question about 8 3/4 rear ends

All centers will fit the housings. 741 the oldest and weakest. 742 middle in age and the strongest. Thickest pinion. 489 is the newest and second strongest. The pinion is tapered. The 742 and 489 are strong enough. 741 throw away or sell. Don't forget you have two different splines that were offered on the pinions for the yoke. Also there are two different size yokes used as well.