PRW 2440001 Black 8.00" OD External Balance Steel Damper for Chevy 400/383 1970-80 - EOL 12/31/2010 Exceeds SFI 18.1 specifications Easy to read laser engraved timing marks Accurate crank bore for a proper pressed fit Manufactured from high grade billet carbon steel forgings Available in black epoxy or polished steel with an epoxy clear coat