I'm going to upgrade my rear gears to 3.73 and my drive shaft to aluminum one. What I'm stuck on is upgrading to 31 spline rear end. In the future if I upgrade the HP will there be a problem with 28 spline rear that I currently have? And besides being able to handle more power what are some other benefits to upgrading to a 31 spline rear end? Thanks.
The main emphasis on going to 31 spline is for strength. If you are running 400+ hp and launching on slicks, yes it's recommended. If this is on street tires and everything is in good shape, 28 spline is plenty sufficient.