HoleShot 2400 for GM 1965 to 1991 TH400, 425, 375 and 1968 to 1981 TH350, 375B (not 350C) are for serious-minded performance enthusiasts and offer additional strength and durability features not found in our Tork Master or Traveler series of converters. The Holeshot converter is an excellent choice for vehicles with some performance engine modifications, particularly big cams that tend to reduce low-end power and torque. The higher stall speed of this converter will launch the car in a higher rpm range where more torque is readily available, resulting in quicker acceleration. Holeshot converters feature furnace brazed impeller fins and turbine, new precision alloy impeller hub and new heavy duty needle bearings. Other features include fully balanced and pressure tested by expert technicians. If your vehicle is equipped with a plate type nitrous system or supercharger, please refer to the Nitrous Holeshot line of converters. Notes: Stall speed listings are based on engines producing 230lb. ft. of torque at 2,500 rpm. More torque at 2,500 rpm will give you more stall speed, less torque at 2,500 rpm will give you less stall speed than the stall speed ratings indicated. Higher stall converters can generate more heat, so we highly recommend adding a transmission cooler. This converter is Not recommended for supercharged, plate-type nitrous oxide or trans-brake applications. The product images shown are for illustration purposes only and may not be an exact representation of the product. 10.75 in. bolt circle.