4L80E Overdrive Planetary. This overdrive planetary assembly is redesigned with a billet steel drive plate to eliminate spline/housing failure in high horsepower and extreme applications. Fits 2002-On. Top Hat is made from 4140 HTSR billet steel and is contoured to the planetary housing to eliminate any possibility of separation under load. 100% drop-in product. No core exchange required.
Sprag for the late (2002-On) design shown below: