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In-Store Pickup Location

Doug Thorley Tri-Y Headers THY-375Y-C

Headers, Tri-Y, Steel, Silver Ceramic Coated, Chevy, GMC, Car, Truck, Small Block, Pair

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

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Brand: Doug Thorley Headers

Manufacturer's Part Number: THY-375Y-C

Part Type: Headers

Product Line: Doug Thorley Tri-Y Headers

Summit Racing Part Number: DTE-375Y-C

UPC: 812721020621

Header Style: Tri-Y

Header Material: Steel

Header Finish: Silver ceramic coated

Weld-Up: No

Primary Tube Outside Diameter (in): 1 5/8 in.

Flange Style: Standard

Collector Attachment: Weld-on

Collector Diameter: 2.500 in.

Collector Reducers Included: No

Tuned: No

Primary Tube Gauge: 14-gauge

Flange Thickness (in): 3/8 in.

Bolts/Studs Included: Yes

Gaskets Included: Yes

Crossover Pipe Included: No

Catalytic Converter(s) Included: No

Motor Mounts Included: No

Transmission Mount Included: No

Quantity: Sold as a pair.

Notes: 3 bolt flange must be welded to exhaust system. Fits with straight or angle plug heads. Will not seal properly on D-port cylinder heads.

In-Store Pickup: Choose In-store pick-up (OH, NV, GA, TX) on our web site.

Thorley headers are designed to outflow your stock exhaust manifolds. They are designed with an emphasis on maximum low and mid range torque, while making ample horsepower throughout the RPM range. The Tri-Y 4:2:1 configuration builds the most power in the middle rpm range, which is great for towing and 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. 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

Questions & Answers Ask a Product Question
Q:

What pair of DTs will work on my 67 Camaro? I'm running a sbc 350 with a 4 spd. I liked the DTE376Y1C but will not work on my car. It read auto transmission only. Please advise.
Thank you
Rich Wai

Asked by RICHARD on March 29, 2016

A:

Thank you for your question. DTE 376Y1C would be the proper set of headers for your application.

Summit RacingSummit Racing Answer - June 23, 2016

Answer This Question

Q:

Looking at photo, the outlet flange looks like it
is very close to being up to or into the X frame.
How far from the X-frame is this 3 bolt flange when installed in 56-61 Corvettes? Will these headers mount the generator found on either the left or right side of the engine?
Do these headers need special short plugs?

Does the emergency brake cable touch the headers?

Does the clutch linkage pivot arm touch these headers?

What is the torque improvement at 4000 RPM above the stock manifolds used on 1965 Fuel Injected Corvette engine?

What is the increase in horsepower for the 270hp
283 with the stock 222/224 performance cam?

Asked by BARR on May 03, 2017

Answer This Question

+See All Questions (2)

Most Helpful Reviews Review This Product

4 Customer Reviews for Doug Thorley Headers THY-375Y-C - Doug Thorley Tri-Y Headers

Average Customer Review

5 Star

(1)

4 Star

(2)

3 Star

(0)

2 Star

(0)

1 Star

(1)

+See All 4 Reviews

headers for 74 NOVA

Summit RacingSummit Racing Verified Purchase

DTE-375Y-C
Tight fit on drivers side. Spark plugs easier to install ( Straight plug )

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Reviewer: from TX

Date: November 22, 2018

Appearance
Ease of Installation
Price/Value
Quality

Easier than most

Summit RacingSummit Racing Verified Purchase

DTE-375Y-C
There were clearance issues, but not as bad as most. Quality product.

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Reviewer: from AZ

Date: August 30, 2018

Appearance
Ease of Installation
Price/Value
Quality

doug throley headers

Summit RacingSummit Racing Verified Purchase

DTE-375Y-C
they fit great no clearance issuse. They look good on the car.very great product

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Reviewer: from NY

Date: January 12, 2016

Appearance
Ease of Installation
Price/Value
Quality

375Y-C 68 EL Camino

Summit RacingSummit Racing Verified Purchase

DTE-375Y-C
overall look of the header was great but could not be installed on vehicle left side hit frame and trans shift linkage, right side could not even line up with head because of frame. Summit rep was great sent them back & exchanged for Hedman's

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Reviewer: from CA

Date: July 01, 2015

Appearance
Ease of Installation
Price/Value
Quality

Some parts are not legal for use in California or other states with similar laws / regulations

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