Fuel Injector Lines Fit For the 1989-91 Cummins Engine 12V 5.9L 3960783 3960784

Fuel Injector Lines for Cummins

These fuel injector lines deliver diesel to the injectors for 1989-1991 Cummins 12V 5.9L engines; OEM cross-reference numbers 3960783 and 3960784.

Overview

These fuel injector lines are precision-formed to supply high-pressure fuel to each cylinder on 1989-1991 Cummins 12V 5.9L engines. Designed as a direct replacement set, these fuel injector lines restore proper fuel delivery and engine performance. They are intended for diesel technicians and owners maintaining Cummins-powered equipment.

Built For Performance

• Manufactured from heavy-duty steel to withstand high fuel pressure
• Pre-bent to match the original routing for a hassle-free installation
• Includes both injector line 3960783 and 3960784 for complete coverage
• Resists corrosion and fatigue for long service life
• Tested for proper flow and fitment before packaging

Fits These Machines

• for 1989 Cummins 12V 5.9L engine
• for 1990 Cummins 12V 5.9L engine
• for 1991 Cummins 12V 5.9L engine

On-The-Job Use

• Used in Dodge Ram pickup trucks with Cummins 12V 5.9L diesel
• Common on agricultural and industrial equipment powered by Cummins 5.9L
• Requires replacement when injector lines are worn, leaking, or damaged
• Ideal for engine rebuilds or fuel system overhauls

Specs At A Glance

Good To Know

Q: Are these injector lines a direct fit for my 1991 Cummins? A: Yes, these lines are manufactured to match the original specifications for 1989-1991 Cummins 12V 5.9L engines, but verify your specific engine serial number before installation.

Q: Do these lines come as a complete set? A: The set includes both injector lines (part numbers 3960783 and 3960784) needed for a six-cylinder engine block.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.