Vortech Superchargers 10-Rib 3.87" Pulley Tall Offset 4MA031-387
10-Rib Tall Offset Supercharger Pulley for Marine & Mopar Applications
The Vortech Superchargers 10-Rib 3.87" Tall Offset Pulley (PN 4MA031-387) is designed for supercharger drive systems that require a tall-offset pulley to maintain proper belt alignment. This pulley is commonly used in Vortech Marine supercharger systems and Paxton Small Block and Big Block Mopar applications where standard-offset pulleys will not correctly position the drive belt.
Featuring a 3.87-inch diameter and a durable 10-rib profile, this pulley provides increased belt contact area and stable power transfer in high-load environments. The tall-offset design helps maintain consistent belt tracking, supporting belt longevity, steady boost delivery, and long-term supercharger reliability in demanding marine and high-performance Mopar setups.
Features & Benefits
- 10-rib design increases belt grip and minimizes slip
- Tall offset configuration ensures correct belt alignment
- Designed for Vortech Marine supercharger systems
- Compatible with Paxton Small Block and Big Block Mopar applications
- Precision-machined for durability and consistent performance
Quick Specs
- Manufacturer: Vortech Superchargers
- Part Number: 4MA031-387
- Pulley Diameter: 3.87"
- Rib Count: 10-Rib
- Offset: Tall Offset
- Application: Vortech Marine; Paxton Small Block & Big Block Mopar
Important Notes
- Designed specifically for tall-offset pulley applications
- Not interchangeable with standard-offset 10-rib pulleys
- Proper pulley diameter selection is critical for safe supercharger operation
- Professional installation is strongly recommended
Emissions & Legal Notice
- NOT AVAILABLE OR LEGAL FOR SALE IN CALIFORNIA
- For off-road, marine, and competition use only
- Installation on emissions-controlled vehicles operated on public roads may violate U.S. federal emissions regulations
Why Buy from Beefcake Racing?
Beefcake Racing is an authorized Vortech and Paxton dealer with extensive experience supporting marine and Mopar supercharger applications. Our team can help verify correct pulley offset, diameter, and belt compatibility to ensure reliable, long-term performance.
Email: sales@beefcakeracing.com
Phone: 1-855-827-7223
CA Residents: WARNING: Cancer and Reproductive Harm www.P65Warnings.ca.gov
