Ford Performance M-8510-A351 Crank Pulley Spacer

4 Bolt Crank Pulley - .350 in. Thick - To Achieve Proper Belt Alignment Used For Proper Pulley Alignment Drilled For 3 And 4 Bolt Damper Made in the USA Product Documents: Installation Instructions Ford Performance Parts - Crank Pulley Spacer P/N M-8510-A351: These crankshaft spacers are specifically designed for use with Ford Racing's crank dampers to achieve proper belt alignment on earlier model 5.0L and 5.8L engines. They are precision-machined on CNC equipment for a perfect fit, have a 3 or 4-bolt pulley pattern, and are available in three thicknesses for different engines.