Thinking of this gear to replace a noisy 3.91 in a 742 case I have. Right now I'm running a 489 case with 3.55 it's fine on the expressway with my 28" drag radials but a bit soft off the line. In the future I will replace the 360 with a 426" sb so the torque will be way up and HP should be about 100 more. Who makes the 3.73, I am looking for a hi quality set, the 742 has new bearings and clutch pack, also will add hi strength axles at the same time.