Outdated Internet Browser Detected

It appears that the Internet Browser you are using to connect to SummitRacing.com is outdated and insecure. To continue to use SummitRacing.com, you must upgrade your browser to a newer, secure version. Use these links to help you upgrade your browser.

In-Store Pickup Location Close

Doug Thorley Headers 309-C

Get Free Shipping with Your Order over $99!

Headers, Shorty, Steel, Ceramic Coated, Chevy, GMC, Pickup, SUV, 4.8, 5.3L, Pair

Estimated Ship Date: Today Would you rather pick it up? Select Location

  • Order this item and get free delivery and handling on your entire order! Offer excludes truck freight fees. Valid on orders shipped in the contiguous United States.

View Similar Products

Manufacturer's Part Number: 309-C
Part Type: Headers
Product Line: Doug Thorley Headers
Summit Racing Part Number: DTE-309-C

Header Style: Shorty
Header Material: Steel
Header Finish: Silver ceramic coated
Weld-Up: No
Primary Tube Diameter (in): 1 5/8 in.
Collector Attachment: Stock flange
Collector Diameter: 2.500 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
Cross Over Pipe Included: No
Catalytic Converter(s) Included: No
Motor Mounts Included: No
Transmission Mount Included: No
Quantity: Sold as a pair.
In-Store Pickup: Choose In-store pick-up (OH, GA, NV) on our web site.

Backed by 40-plus years of knowledge and experience, 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 made 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, nickel chrome plated 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.

Warranty

Most Helpful Reviews Review this Product

4 Customer Reviews for Doug Thorley Headers 309-C - Doug Thorley Headers

Average Customer Review

5 Star

(3)

4 Star

(1)

3 Star

(0)

2 Star

(0)

1 Star

(0)
+See All 4 Reviews

doug thorley headers

Summit RacingSummit Racing Verified Purchase

The directions that I received are VERY POOR. They do not tell you that you have to drop the exhaust in order to remove the drivers side manifold and install the header, as for the right side ,the instructions are correct but that's the only side they give instructions for. As for the headers they did improve the performance of my truck. I have seen an increase in my fuel mileage also when towing my 31ft. travel trailer. ...read more

0 of 0 found this review helpful.

report abuse

Report Abuse Close

If you feel that this review is inappropriate and should be removed from the site, report it to us by clicking the "Report Abuse" button below.

Cancel

Reviewer: LEONARD from PA

Date: October 12, 2014

Appearance
Ease of Installation
Price/Value
Quality

Well made headers and fit my swap perfectly

Summit RacingSummit Racing Verified Purchase

I purchased these headers for a 72 K20 LS swap with motor moved forward 2" and a hydraulic clutch. I had to clearance the drivers side frame rail a bit, but otherwise they fit great, are very stout and have factory type flanges/gaskets.

0 of 0 found this review helpful.

report abuse

Report Abuse Close

If you feel that this review is inappropriate and should be removed from the site, report it to us by clicking the "Report Abuse" button below.

Cancel

Reviewer: CHRIS from MD

Date: July 17, 2014

Appearance
Ease of Installation
Price/Value
Quality

headers

Summit RacingSummit Racing Verified Purchase

Really happy with the purchase and performance of my headers

0 of 0 found this review helpful.

report abuse

Report Abuse Close

If you feel that this review is inappropriate and should be removed from the site, report it to us by clicking the "Report Abuse" button below.

Cancel

Reviewer: LEONARDO from CA

Date: June 16, 2014

Appearance
Ease of Installation
Price/Value
Quality

Great Product

Summit RacingSummit Racing Verified Purchase

Great design and welded professionally. If using on a stock crossover, buy new gaskets and don't use the ones in the kit.

0 of 0 found this review helpful.

report abuse

Report Abuse Close

If you feel that this review is inappropriate and should be removed from the site, report it to us by clicking the "Report Abuse" button below.

Cancel

Reviewer: CALEB from WY

Date: March 26, 2014

Appearance
Ease of Installation
Price/Value
Quality

Some parts are not legal for sale or use in California on any pollution-controlled motor vehicles

Back To Results
Email this page Close
Close