ARP Oversized Stud Kits Save Damaged Chevy LS Blocks From the Scrap Pile

Anyone who has spent time building LS engines has seen it happen. A perfectly good factory or aftermarket Chevy LS-series block gets tossed on the scrap pile because the cylinder head or main cap threads are damaged beyond repair. It’s a frustrating and expensive way to lose the foundation for your next build.

The engineering team at ARP has a fix. The fastener specialist has developed special studs designed specifically to bring those damaged blocks back into service.

For Gen III/IV LS blocks, ARP offers special stud kits that use an oversized 1/2-13 thread at the bottom, where the stud threads into the block, and a standard 7/16-20 thread at the top. The larger lower thread gives the stud fresh material to bite into once damaged threads are repaired, while the standard upper thread keeps everything compatible on the nut side.

The result is a way to salvage a block that would otherwise be written off.

ARP offers these Gen III/IV kits in two materials, depending on the level of clamping strength your build demands:

• ARP2000™: ARP’s proprietary material, nominally rated at 220,000 psi tensile strength.
• Custom Age 625+: Offered in a new kit, part number 434-4348, with studs rated at 260,000–280,000 psi.

For high-horsepower or boosted combinations where clamping force is critical, the Custom Age 625+ kit gives builders a significant step up in strength.

ARP also offers a main stud repair kit for RHS aluminum blocks. That kit, part number 234-5803, is manufactured from ARP2000™ material.

Like every other ARP stud, these repair studs are built to a premium standard. They use a centerless ground, which ensures perfect concentricity. The threads are rolled after heat treatment. Rolling the threads (rather than cutting them) after heat treatment produces superior grain flow.

You can learn more about these kits right here on ARP’s website.