These systems for the SC10 and T4 series of vehicles are of steel construction, keeping to relatively the same overall weight that you are used to with your steel OEM drivetrain, but giving you the added benefit of MIP Pucks. No longer will diff outdrives and CV bones wear simultaneously, with the Puck system all that is needed is to easily change Pucks when necessary, and the drivetrain stays tighter and fresher for a longer time. Drive on over to www.miponline.com for more info.