1.80 "Extreme Duty" Planetary, Standard Length

"EXTREME DUTY" PLANETARY, STD LENGTH, STEEL CARRIER, BILLET BOLT-ON OUTPUT SHAFT, STRAIGHT CUT GEARS, 1.80 RATIO

The Coan Racing COA‑12721A “Extreme Duty” Planetary Assembly is a heavy-duty, performance-enhanced internals package engineered specifically for GM Powerglide transmissions. Featuring a robust steel carrier and straight-cut gear set precisely machined to a 1.80 ratio, this planetary assembly is designed to withstand the extreme stress and torque demands of competitive racing and high-performance street use.

A standout feature is the billet bolt-on output shaft, which adds durability and enables swift servicing without disturbing internal components, ensuring long-lasting integrity and simplified maintenance.

Built to Coan Racing’s rigorous performance standards, the COA‑12721A offers seamless compatibility with standard-length (28″) Powerglide cases, delivering consistent torque multiplication and gear engagement without the need for machining or fitment modifications. Whether enhancing a drag strip powerhouse or reinforcing a high-horsepower street drivetrain, this rebuilt planetary assembly provides formidable strength, precise gear indexing, and unrivaled reliability in demanding automotive environments.