Prothane 4-504-BL Motor Mount Insert for Small Block Mopar B/RB-Series, Black

Upgrade the drivetrain support of your classic Mopar with the Prothane 4-504-BL Motor Mount Insert. Designed for Small Block Mopar and B/RB-Series applications, this black polyurethane insert helps reinforce the engine mounting system while maintaining a practical balance of performance, durability, and street-friendly operation. It is engineered for Mopar A-Body, B-Body, and E-Body vehicles from 1973 through 1989, making it a focused replacement or upgrade for compatible factory-style spool motor mounts.
Constructed from durable polyurethane, the Prothane 4-504-BL insert is designed to resist deterioration from common automotive fluids, weather exposure, and repeated engine movement. Its firm material helps reduce excessive mount deflection and supports more consistent drivetrain positioning under acceleration, shifting, and load changes. The black finish provides a clean, understated appearance suitable for restoration, performance, and maintenance projects.
This motor mount insert is supplied as a kit for installation in compatible applications. Verify vehicle configuration, engine series, mount style, and model-year fitment before ordering to help ensure proper compatibility. The insert is intended for use with the specified Mopar spool-style mounting arrangement and is not a universal replacement for every engine mount design. Prothane part number 4-504-BL provides a dependable solution for renewing worn mounting support while preserving the original vehicle layout.

Features:

• Brand: Prothane

• Part Number: 4-504-BL

• Product Type: Motor mount insert

• Material: Durable polyurethane

• Color: Black

• Application: Small Block Mopar and B/RB-Series engines

• Vehicle Fitment: Mopar A-Body, B-Body, and E-Body vehicles from 1973 through 1989

• Mount Style: Spool-style engine mount insert

• Package: Kit