Hawks Motorsports is pleased to offer our clients the following 100-1201 SBC Header Bolts, ARP Chromoly 12-Point, 3/8"-16 x 0.750", Set of 12. These ARP header bolts are designed for Chevrolet Small Block applications and feature a 3/8"-16 thread, 0.750-inch underhead length, compact 12-point head, and 8740 chrome moly construction with a black oxide finish. The set includes 12 header bolts.

For the gearhead building a serious small-block Chevy, header hardware is one of those details that deserves more attention than the cheap hardware-bin bolts that usually end up on an engine. When you're squeezing headers into a tight engine bay, the compact 12-point head gives you better wrench access around the tubes, while the black oxide chromoly construction gives the engine bay the purposeful look you'd expect on a performance build. Whether you're freshening up a street-driven SBC, assembling a weekend warrior, or putting the finishing touches on a full-blown engine project, ARP 100-1201 puts quality fastener hardware where it belongs—at the header flange.

The 100-1201 kit uses a 3/8"-16 thread and 0.750-inch underhead length and is cataloged by ARP for generic Chevrolet Small Block applications. The 12-point head is designed for use where access around header tubes can be limited.

KEY FEATURES

• Part Number: 100-1201
• Manufacturer: ARP
• Application: Chevrolet Small Block
• Product Type: Exhaust header bolt kit
• Thread Size: 3/8"-16
• Underhead Length: 0.750" / 19.0 mm
• Head Style: 12-point
• Material: 8740 Chrome Moly
• Finish: Black oxide
• Quantity: Set of 12
• Compact 12-point head for improved access around header tubes
• Designed for Chevrolet Small Block header applications
• Performance-oriented replacement hardware for engine builds and restorations

PRODUCT SPECIFICATIONS / PRODUCT DETAILS

ARP's current product information identifies 100-1201 as an SB Chevy 3/8 x .750" 12-point header bolt kit, using 8740 chrome moly material, with 12 bolts and a 0.750-inch underhead length.

VEHICLE FITMENT / FITS THE FOLLOWING MODELS

Chevrolet Small Block Applications

ARP catalogs 100-1201 by Chevrolet Small Block engine application, rather than assigning the part to a specific vehicle year or model.

This makes the kit applicable to vehicles equipped with compatible Chevrolet Small Block engines, subject to the header flange and fastener requirements of the specific application.

Potential vehicle applications may include Chevrolet-powered:

• Camaro
• Chevelle
• Nova
• Impala
• Corvette
• C10/C20/C30 and other Chevrolet trucks
• Other vehicles equipped with compatible Chevrolet Small Block engines

Important: Vehicle fitment should be based on the engine and header application, not simply the vehicle model. Verify that the header manufacturer specifies 3/8"-16 header fasteners with approximately 0.750" underhead length before ordering.

IMPORTANT APPLICATION NOTES AND EXCLUSIONS

• Designed for Chevrolet Small Block applications.
• 3/8"-16 thread.
• 0.750" underhead length.
• 12-point head design.
• 8740 chrome moly construction.
• Black oxide finish.
• Sold as a set of 12.
• This is a bolt kit, not a header stud kit.
• Verify header flange thickness and available thread engagement before installation.
• Do not assume this kit fits Gen III/IV LS or Gen V LT engines; those engines use different header fastener applications.
• Verify the specific header and cylinder-head combination before ordering.

INSTALLATION NOTES

• Verify the header manufacturer's required fastener size and length before installation.
• Confirm the 3/8"-16 thread matches the cylinder-head header bolt holes.
• Verify that the 0.750" underhead length provides appropriate thread engagement without bottoming in the cylinder head.
• Check clearance between the 12-point heads and header tubes before final tightening.
• Clean the cylinder-head and header flange mounting surfaces before assembly.
• Follow the applicable ARP installation and torque recommendations.
• Use the appropriate ARP-recommended fastener lubricant and installation procedure.
• Tighten fasteners evenly to properly seat the header flange.
• Recheck header fastener torque after initial heat cycles when appropriate for the specific engine and header installation.

FREQUENTLY ASKED QUESTIONS

What engines does ARP 100-1201 fit?

ARP identifies 100-1201 for Chevrolet Small Block applications.

What size are the ARP 100-1201 header bolts?

They use a 3/8"-16 thread and have a 0.750-inch underhead length.

Are these 12-point header bolts?

Yes. ARP 100-1201 uses a 12-point head.

What are ARP 100-1201 bolts made from?

ARP identifies the material as 8740 Chrome Moly.

What finish do these header bolts have?

The 100-1201 kit uses a black oxide finish.

How many bolts are included?

The kit contains 12 header bolts.

Will these fit a Chevrolet Camaro?

They can be used on a Camaro equipped with a compatible Chevrolet Small Block and headers requiring 3/8"-16 fasteners. Vehicle year and model alone are not sufficient to confirm fitment.

Will these fit an LS engine?

Do not assume so. Gen III/IV LS engines use different header fastener specifications and ARP offers dedicated LS header bolt applications. Verify the exact engine and header combination before ordering.

Are these header studs?

No. 100-1201 is a header bolt kit. ARP also offers separate Small Block Chevy header stud k