if you have the 741 case you are limited to 2 available ratios 3.55 and 3.73 there are no aftermarket gear sets made in the North America anymore except those used by OEM ( Ford , GM , Chrysler ) factory builds ,, Motive ( Richmond ) made in Italy but a premium gear set in the orange box , Yukon a premium gear set made in China ,,,, all the others are Chinese / Asian manufactured some good some bad . i prefer to use only Motive gears first ,, then Yukon gear when i build my 8-3/4 differentials now depending on what case is used and gear ratio that is available for that case.