The cases are made from ASTM A536 65-45-12 nodular ductile iron here in the U.S.A.
The cases have chrome moly caps.
• The 3.250 (carrier bearing O.D.) case is for 35 and 40 spline axles.
• The 2.891 (carrier bearing O.D.) case is for 28 and 31 spline axles.
We are using 170,000 psi. minimum tensile strength aircraft quality main cap bolts. Standard grade 8 bolts are 150,000 psi. minimum tensile strength. It utilizes the thrustblock anti ring gear deflection device.
Stock 9" Ford gears will NOT work with these cases.
The picture shows a comparison between a standard case and ours.