Kooks GM Gen5 LT-1 1 7/8in GM Gen5 LT-1

Single Bank Header Flange Built to Kooks Spec for GM Gen5 LT1 Custom Fabrication

The 70-024 is a single bank 1 7/8 inch header flange for GM Gen5 LT1 engines, providing fabricators with the precise bolt pattern and port opening geometry required to build or repair headers for fifth generation LT1 powered vehicles including the 2014 to current Chevrolet Corvette, Camaro SS, and other LT1 applications. The Gen5 LT architecture brought changes to the cylinder head exhaust port layout compared to the previous generation LS family, and using a flange designed and machined specifically for the LT1 ensures correct port alignment and an accurate bolt hole pattern from the start of the fabrication process.

Kooks produces the 70-024 to the dimensional specifications of their own Gen5 LT1 header production, making this flange a direct reference to the same starting component used in their commercial header builds. Stainless steel construction provides the flatness retention and heat resistance needed in a high temperature exhaust application. Fabricators building custom LT1 headers, shops repairing cracked flanges, and racers working on one off header configurations will find this flange the correct and accurate starting point for their build. A complete V8 installation requires two flanges, one per cylinder bank.

Key Features

• Single bank flange for one cylinder head of a GM Gen5 LT1 engine
• 1 7/8 inch port opening for standard LT1 primary tube diameter
• Precision machined to Kooks LT1 header production specifications
• Correct bolt hole pattern for Gen5 LT1 cylinder head exhaust ports
• Stainless steel for flatness retention and corrosion resistance
• Suitable for custom header builds and flange replacement on existing headers

What’s Included

• 1 x this flange single bank 1 7/8 inch Gen5 LT1 header flange

Specifications

Specification	Detail
Part Number (MPN)	70-024
UPC	Contact us for UPC
Port Opening	1 7/8 inch
Coverage	Single Bank (One Cylinder Head)
Application	GM Gen5 LT1 Engines
Material	Stainless Steel
Use	Custom Header Fabrication and Flange Replacement

Frequently Asked Questions

What engine does this flange fit?
This flange is designed for GM Gen5 LT1 engines found in 2014 and later Chevrolet Corvette Stingray, Camaro SS, and other LT1 powered platforms.

Is this flange compatible with the older LS1 head pattern?
No. The Gen5 LT1 cylinder head uses a different exhaust port bolt hole layout than the LS family. Use the 7046-AS for LS1 applications and this flange for Gen5 LT1 applications.

Does this flange cover both sides of the engine?
No. This flange is a single bank flange for one cylinder head. Two flanges are required for a complete V8 header set.

What primary tube diameter does this flange accept?
The port opening is 1 7/8 inch, designed to accept 1 7/8 inch primary header tubes for TIG welding.

Is this flange the correct flange for the LT4 engine as well?
The LT4 uses the same Gen5 architecture as the LT1 but verify cylinder head port dimensions with Kooks before ordering for an LT4 application, as supercharger related revisions may affect port geometry.

What material is this flange made from?
Stainless steel, providing dimensional stability and resistance to the warping that can affect mild steel flanges under repeated thermal cycling.

How are primary tubes attached to this flange?
Primary header tubes are inserted into the port openings and TIG welded to the flange using stainless steel filler compatible with the flange material.

Does this flange include gaskets or bolts?
This flange is the flange plate only. Exhaust gaskets and header bolts appropriate for the LT1 application are sold separately in the Kooks accessory lineup.

Can this flange be used to repair a cracked Kooks LT1 header?
Yes. Fabricators can use this flange as a replacement flange when an existing LT1 header flange cracks or warps beyond usable condition.

Is this flange the same flange Kooks uses in their production LT1 headers?
Yes. This flange is machined to the same dimensional specifications used in Kooks production LT1 header manufacturing.

Installation Instructions

1. Confirm this flange matches the Gen5 LT1 cylinder head bolt pattern before beginning fabrication.
2. Test fit this flange against the cylinder head with an exhaust gasket in place to verify port alignment and bolt hole registration.
3. Remove the flange from the engine and position it in the fabrication setup for primary tube attachment.
4. Insert 1 7/8 inch primary tubes into the port openings and tack weld to set the header geometry.
5. Complete all primary tube to flange welds with TIG using stainless filler material.
6. After fabrication is complete, install the header assembly on the LT1 engine with the appropriate gasket and torque fasteners to the Kooks specification.

Prop 65 Warning

WARNING: This product can expose you to chemicals including Chromium and Nickel, which are known to the State of California to cause cancer, birth defects or reproductive harm. For more information go to www.P65Warnings.ca.gov.