1310 (also 297X): The 1310 (shown) is a 1/2 ton u-joint used in driveshafts for many Jeep applications and is retained via external snap rings; the ones that slightly resemble a pretzel. The 297X u-joint is effectively the same size but with internal snap rings used for steering knuckle joints on most Dana 44 and Corporate 10 bolt front axles.
1330: This is a 3/4 ton driveshaft u-joint most often found at the pinion yoke going into Dana 60 front or rear axles. The 1330 shares the same cap size as the 1310 but with a larger cross.
1350: Most 1 ton trucks of yester-year used these joints (middle joint in picture) in their driveshafts but could be found in 3/4 ton and 1/2 tons occasionally. Note the cross is the same size as the 1330 to its left but the bearing caps, and therefore the trunions that they pivot on are larger, i.e. more strength.
1410: In recent years, the Super Duty line from Ford, and Chevy and Dodge H.D. series are using even beefier joints in their driveshafts. The 1410 can be considered a 1.25 ton joint and is appropriate when behind the torque monster diesel engines from the Big Three.
1480: This joint (farthest right) is most commonly a steering knuckle joint rather than a driveshaft u-joint and resides inside the knuckles of Dana 60 and 70 front axles. In a driveshaft application, it could be considered as a 2 ton joint. Keep in mind that a steering knuckle joint sees 3-5 times as much torque as the driveshaft joints strictly from the ring and pinion reduction. It is further multiplied by having the steering turned to anything other than straight.
297X vs 760X: Spicer phased out the old reliable 297X u-joint and replace it with the new 760X. Shown is a new Spicer 5-760X replacement joint next to the old 5-297X. These joints are an updated design and have a cold-forged cross which has repeatedly been shown to be much stronger than the 297’s hot-forged cross, with a much longer fatigue life. This should help to further put the brakes on broken u-joints.