Due to the notorious bucket wear issues on the YXZ, BC only offers shim in buckets with DLC coating. Requires BC spring/retainer kit BC0950B in order to use. Made from aerospace grade, 4140 chromoly steel alloy and completely CNC machined from heat-treated billet round bar. Heavy-duty wall thickness eliminates distortion and cam face depression, while reducing overall weight from non-critical stress areas. Nitrided and polished to a surface hardness of 60RC for minimal wear. Provides lower friction with cam lobes and cylinder head lifter bores for improved durability.