Tapered bearings will generally last the longest but the non adjustable "green" bearings can and do last a long time also if they're the second generation that utilizes a divorced flange/retainer. The nice thing about the non adjustable bearings is they center the wheels in the wheel house better than adjustable's and they need now adjustment when installed. Here's a good write up on Dr. Diff's page telling about the different Green bearings
Why Green Bearings? - Quality Body Shop Drivetrain
