1955-1985 Chevrolet Small Block except the 400 cid engine, 153 toothAs performance levels increase, an O. E. style flexplate just won't cut it and a stronger option is a necessity to prevent transmission and or converter failure. B&M has you covered with our high performance flexplate designed for 1955 1985 small block Chevy V8 engines (internally balanced) with two piece rear main seal. Features include high tensile strength steel construction to resist elongation and cracking, 10. 75 inch bolt pattern, 153 tooth