Exhaust Headers Shorty for Dodge Chrysler Plymouth Small Block (1968-1980) 273-360 5.2L 5.6L

High-Flow Shorty Exhaust Headers for 1968-1980 Dodge, Chrysler, Plymouth (LA Small Block / A, B, E-Body)

What It Does: Replaces the restrictive, heat-retaining factory cast iron manifolds with mandrel-bent steel headers to optimize exhaust scavenging and significantly reduce backpressure.

The Stock Weakness

The factory "log" style manifolds found on the Mopar LA-series engines were engineered for low-cost mass production and tight engine bay packaging rather than volumetric efficiency. These heavy cast iron components create massive turbulence as exhaust pulses from adjacent cylinders collide within the common chamber. This restriction leads to significant heat soak in the cylinder heads and creates parasitic drag on the piston’s upstroke, robbing the engine of potential horsepower. Furthermore, decades of thermal cycling often result in hairline fractures and warped mating surfaces, leading to persistent exhaust leaks that can affect O2 readings and fuel trim in later models.

The Engineering Solution

These shorty headers utilize heavy-duty CNC-machined 7/16" head flanges to provide a warp-resistant, airtight seal against the cylinder head ports. Constructed with mandrel-bent tubing, the headers maintain a uniform internal diameter throughout every radius, preventing the bottlenecking found in stock units. This smooth flow path allows exhaust gases to maintain higher velocity, creating a vacuum effect that pulls spent gases out of the combustion chamber more efficiently—a process known as scavenging. The TIG and MIG welded construction ensures structural integrity under high Exhaust Gas Temperatures (EGTs). By streamlining the transition from the 1 3/4" x 1 1/2" inlets to the 2.25" collectors, this system delivers gains of up to 13HP and 11 lb-ft of torque.

Technical Specifications

Compatibility

• Dodge: Challenger, Charger, Coronet, Dart, Aspen, Diplomat, Magnum, Mirada, Dakota
• Plymouth: Barracuda, Cuda, Duster, Valiant, Volare, Satellite, Roadrunner, GTX, Fury, Belvedere
• Chrysler: Cordoba, LeBaron, New Yorker, Newport, Imperial, Fifth Avenue
• Engines: 273, 318 (5.2L), 340 (5.6L), 360 (5.9L) Small Block

The Mopar Muscle Standard

These headers are designed to deliver the iconic small-block Mopar rumble and increased throttle response demanded by classic muscle enthusiasts. Built for high-heat durability and maximum clearance, they provide the performance bridge between a stock cruiser and a street-strip machine.

Common Questions

Which Mopar engines do these shorty headers fit?
They are built for Dodge, Chrysler, and Plymouth LA-series small block V8 engines, covering the 273 (4.5L), 318 (5.2L), 340 (5.6L), and 360 (5.9L).

What are the inlet, collector, and flange dimensions?
These headers feature 1-3/4" x 1-1/2" ports, heavy-duty 7/16" CNC-machined cylinder head flanges, and 2.25" collectors.

What kind of power gains can I expect over stock cast iron manifolds?
By replacing the restrictive factory log-style manifolds with mandrel-bent tubing to improve exhaust scavenging, this system delivers gains of up to 13 HP and 11 lb-ft of torque.

Will these fit a Mopar big block engine?
This header set is engineered specifically for Mopar LA small block V8 engines (273, 318, 340, and 360).

How are the header tubes and flanges constructed?
They use mandrel-bent steel tubing for uniform internal diameter across every bend, paired with TIG and MIG welded construction and 7/16" CNC-machined head flanges for a warp-resistant seal.