Installing a quality USA Standard Gear spool is a cost-effective way to get 100% lockup. Installation is easy as they install in place of your differential carrier assembly. Each USA Standard Gear spool is made from high-quality 8620 steel and heat treated for additional strength. A spool is an outstanding choice for dedicated off-road and drag racing vehicles only.
USA standard steel spool for Model 20 with 29 spline axles, 3.08 & up
USA Standard Steel Spool For Model 20 w/ 29 Spline Axles / 3.08+
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M20 3.08 & UP 29spl SPOOL
Differential Spool
ZP FSM20-3-29
Spool