This listing is for a brand new, stock replacement harmonic balancer made from high-strength nodular iron.

It is 6 3/4" in diameter, internally (neutral) balanced, and replaces GM OEM part number 12551537. It fits many of the 1972-1994 small block Chevy 305, 327 and 350 V8 engines in passenger cars and light duty pickups.

You can also use this balancer on other internally balanced small block V8 engines like the 283, 302, 305, 307, 327, and 383 but it may require pulley spacers or different pulleys to get proper belt alignment and the 0° timing mark may not be in same position as your old balancer so timing tab modifications or replacement may be needed.