Aluminum through bolt-bolt case (3.250" bore), 35-spline locker (nodular) or optional 35-spline Detroit Truetrac, MW 28-spline 1350 series pinion yoke, tapered / tapered pinion support, 9" 8620 gear. All MW Thirdmembers include shipping / storage transporter and 3 quarts of gear lube. (75 lbs). Installation - Service instructions can be found on Service Bulletin #0038