Product Description:
This polished stainless steel header bolt set is specified for compatible LS headers with 1/4-inch flanges. It supplies 12 M8 x 1.25 bolts with 12-point heads and a 25 mm (0.984-inch) underhead length.
| Producer | ARP |
|---|---|
| Product type | 12-point header bolt kit |
| Application | GM LS Gen III / Gen IV headers with 1/4-inch-thick flanges and M8 x 1.25 threads |
| Material | Stainless steel |
| Finish | Polished |
| Condition | New performance part |
| Quantity | 12 header bolts with washers |
| Engine / assembly | Required configuration |
|---|---|
| GM LS Gen III | Compatible headers with 1/4-inch flange; M8 x 1.25 cylinder-head threads |
| GM LS Gen IV | Same flange, thread and engagement checks required |
Select by the installed engine and component configuration. Vehicle year alone does not establish compatibility, particularly after an engine swap.
- 12 polished stainless steel 12-point header bolts
- Companion washers
Choose header hardware by the actual flange thickness and threaded engagement. The shorter length distinguishes this kit from the 30 mm version for thicker flanges. Check access around the tubes so the required 12-point socket seats fully on each head.
| Thread | M8 x 1.25 |
|---|---|
| Underhead length | 25 mm / 0.984 inch |
| Header flange | 1/4 inch |
| Quantity | 12 bolts |
| Head style | 12-point |
- Measure flange thickness and confirm the required underhead length before installation.
- Check usable thread depth, washer seating and 12-point socket clearance at every bolt location.
- Use the applicable kit and header-manufacturer lubrication and torque instructions.
Which header flange does this kit match?
The manufacturer specifies a 1/4-inch flange on a compatible LS application.
How long are these bolts under the head?
The manufacturer specifies 0.984 inch, approximately 25 mm.
Is this the same length as 434-1202?
No. This kit is the shorter version. Compare flange thickness and underhead length before choosing either kit.
Are the bolt heads hex or 12-point?
They are 12-point heads.
Does the kit cover both sides of a V8 header installation?
It supplies 12 bolts. Confirm that quantity and the fastener layout against your headers.
If outside the lower 48 states please email us for a shipping quote: Orders@Hawksmotorsports.com
