Details
Thorley headers are designed to outflow your stock exhaust manifolds. These headers increase gas mileage and give your engine more horsepower across the entire RPM range. Their design configuration builds the most power across the RPM range, which is great for everything from street/strip performance, to towing, to steep grades. To make these headers last, Thorley makes them out of durable 14-gauge mild steel with 3/8 in. thick flanges and 5/16 in. collector rings and topped them off with a good looking, silver ceramic finish. To prevent leaks, these headers have an O-ring welded into the flange, in addition to the high-temperature gasket provided.
Unless otherwise noted, these headers are designed to fit the vehicle as it came from the manufacturer.This includes components like cylinder heads, chassis, steering, motor mounts, body mounts and bushings, etc.
If your vehicle is using aftermarket components, parts from other applications, or custom altered parts, then it is the installer's responsibility to verify fitment.
Brand: Doug Thorley Headers
Manufacturer's Part Number: 203-C
Part Type: Headers
Product Line: Doug Thorley Headers
Header: Shorty
Header Material: Steel
Header Finish: Silver Ceramic Coated
Primary Tube Diameter (in): 1 3/4 in.
Collector Attachment: 3-bolt flange
Collector Diameter: 3.000 in.
Tuned: No
Primary Tube Gauge: 14-gauge
Flange Style: Standard
Flange Thickness (in): 3/8 in.
Bolts/Studs Included: Yes
Gaskets Included: Yes
Reducers Included: No
Y-Pipe Included: No
Motor Mounts Included: No
Transmission Mount Included: No
Quantity: SOLD AS A PAIR.
Drivetrain: 2WD
Power Steering: Yes
Power Brakes: Yes
Air Conditioning: Yes
Standard Transmission Column Shift: Yes
Standard Transmission Floor Shift: Yes
Automatic Transmission Column Shift: Yes
Automatic Transmission Floor Shift: Yes
Additional Information
| year make model | 1966-1976 Ford F100, F150, and F250 Truck thy203c |
|---|---|
| Manufacturer | DOUG THORLEY HEADERS |


