Small Block GM Serpentine Pulleys – Crankshaft & Water Pump Options Diameter:3.9" so you know they’re trail-tested

so you know they’re trail-tested and PSC-approved

no nonsense—just the right part for the job

Bigger bearings

Whether you’re out on the trail

or just want to keep things clean and safe

Small Block GM Serpentine Pulleys – Crankshaft & Water Pump Options Diameter:3.9" so you know they’re trail-testedThese PSC serpentine pulleys are built for Small Block GM engines and designed to keep your accessory drive running smooth and efficient. Whether youre dialing in reduction for performance or just want a clean, reliable setup, these pulleys deliver. Precision machined for a perfect fit, theyre tough enough for street builds and custom projects alike. Choose from crankshaft and water pump options to match your setup: PP3400: Crankshaft Pulley 3. 125"