Spectre Torque Converter Bolt & Lock Nut Set was designed to fit General Motors TH350, Powerglide, and most TH400 transmissions. Measuring 3/8 inch-24 by 5/8 inch, these bolts are grade 8 and black oxide plated for corrosion resistance and include security lock nuts. Manufactured using high quality materials, this product is engineered for optimum fit and function.