This is the 10 inch 3500 TO 3800 stall C-4 Torque Converter with 10 1/2 bolt circle. This Converter can be ordered with 24 or 26 Input Spline. Please specify when ordering. This Converter features a billet steel front cover and anti balloon plate hub. Rated to 750 hp. This Converter is fully manufactured by us here at Roadrunner Converters. Buy with confidence. 34 years with Torque Converters our only business. No core charge. Free shipping to lower 48 States. One year warranty. PLEASE SPECIFY 24 OR 26 SPLINE WHILE ORDERING.