Doug Thorley Headers THY-300Y-C are designed to outflow your stock exhaust manifolds. These headers increase gas mileage and give your engine more horsepower across the entire RPM range. The Tri-Y configuration builds the most power in the middle RPM range, which is great for towing and steep grades. To make these headers last, Doug Thorley Headers 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.
Brand: Doug Thorley Headers
Manufacturer's Part Number: THY-300Y-C
Part Type: Headers
Product Line: Exhaust
Header Style: Tri-Y
Header Material: Steel
Header Finish: Silver ceramic coated
Primary Tube Diameter (in): 1 5/8 in.
Collector Attachment: 3-bolt flange
Collector Diameter: 2.500 in.
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
Power Steering Yes
Power Brakes Yes
Air Conditioning Yes
Standard Transmission Column Shift No
Standard Transmission Floor Shift No
Automatic Transmission Column Shift Yes
Automatic Transmission Floor Shift Yes
Will fit with angle plug heads.
May require alternator/generator bracket.
Will require air conditioning bracket on models equipped with "long" style compressor (1988 and earlier).
Specify A/C compressor mounting location. L/S bracket P/N 8506. R/S Bracket P/N 8506.
Doug Thorley Headers carry a lifetime warranty against defects in material and workmanship to the original purchaser. Chrome plated items carry no warranty for finish, other than to be free from defects at the time of purchase, prior to installation. This warranty does not cover damage caused by misuse, abuse, collisions, improper installation, alterations, off-road use, racing use, commercial use, "burn-out" or cracking caused by excessive heat, superchargers, or external heat insulating wrap. Rust or corrosion that occurs after the product is installed is also not covered.
|year make model||1961-1987 GM Truck, Suburban, Blazer, Jimmy|
|Manufacturer||DOUG THORLEY HEADERS|
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