This forged flexplate is for 1986-1999 SBC engines with 1-piece rear main seals. SFI 29.1 approved and internally balanced, they feature 168-tooth count and a dual GM bolt pattern, are sized for stock 3/8" mounting bolts and can be easily drilled for 7/16" diameter high performance torque converter applications. These machined flexplates are .035" thicker than stock with the starter ring welded to both sides of the flywheel for additional strength. Constructed of a high tensile strength material, these resist elongation and cracking and are perfect for stock to mild performance applications.