KRC R-LOK Crankshaft Adapters and Pulleys

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R-LOK Crankshaft Adapters and Pulleys allow for a modular system in which pulleys can be changed in minutes. More concentric than pin-drive or keyway systems, the unique R-LOK design reduces side loads on damper bolts (a problem on mandrel-type systems). Available for Chevy, Ford, and Dodge, these CNC'd anodized aluminum adapters feature weight reduction pockets that do not affect structural integrity.

The SB-Chevy Pro R-LOK Crank Adapter eliminates the need for a long crank bolt that can potentially break off. A steel tab goes in first with a shorter bolt to fasten the damper to the engine; an R-LOK crank adapter mounts over it; all pulleys are then secured to the adapter with a shorter bolt.

KRC Crank Pulleys are CNC-machined from 6061 billet aluminum to the highest tolerances and SAE specifications. They have weight reduction pockets and are treated to C-70 Rockwell hardness. The serpentine pulleys have 30% more surface area for belt contact than most competitor pulleys.

KRC Crank Spacers provide proper alignment for your application. They fit between an R-LOK crank adapter and an R-LOK crank pulley, resulting in correct alignment of the crank pulley belt and water pump pulley (and/or other pulleys).