Ideal for Street rod and Pro-Street usage. Aluminum through bolt case (3.062" bore), heavy duty clutch type posi-traction unit, stock Ford (1330 series) pinion yoke, tapered / tapered bearing pinion support, 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