1937-1948 cars & 1937-1941 pickups. Not an item to be neglected, the critical coupler joins your driveshaft end to the rear end pinion gear. Made of a special high strength steel alloy with exceptional torsional and fatigue strength, this coupler will keep your driveline turning thousands of miles into the future. Connects 6 spline driveshaft end to rear end pinon gear. Manufactured to ultra tight tolerances, offering a no-slop secure fit. Includes correct, specialty made countersunk pins. Specifications: Total Length: 4.40 inch, Outside Diameter: 1.46 inch, Inside Diameter: 1.092 inch. Inside Spline Teeth Diameter: 0.921 inch.