Never fight sharp, gnarly exhaust gaskets again. This bolt-on, manual groove cutter brings machine-shop precision to your garage so you can cut O-ring grooves on LS cylinder heads quickly, accurately, and repeatably — saving teardown, shipping, and shop labor.

Quick pitch: Bolt the jig to your exhaust flange holes, rotate the inner cutter with a 3/4" socket and ratchet, check depth often, and walk away with a perfect O-ring groove sized for reusable Viton O-rings.

What it does / Why you want it

• Replaces expensive machine-shop work for LS exhaust O-ring grooves.

• Makes a repeatable, clean groove so gaskets seal properly and last longer.

• Hand-operated, durable billet construction — keep it in your toolbox and use it on every LS head you or your friends have.

How it works (brief)

1. Bolt the outer jig to your head using the exhaust flange bolt holes (do not force or modify heads beyond instructions).

2. Install the inner rotating cutter, apply lubricant through the oil hole, and rotate using a 3/4" socket & ratchet a few revolutions.

3. Lower the set screw a minimal amount, repeat cutting passes, and check the depth often through the depth inspection hole.

4. Final depth target: 0.115"–0.125". Recheck multiple times to avoid cutting too shallow or too deep.

Specs

• Material: 6061 billet aluminum (fixture)

• Groove size cut: 2.25" Outside Dia. / 2.00" Inside Dia.

• Depth target: 0.115" – 0.125" (must be verified during cutting)

• Drive: 3/4" socket & ratchet (not included)

• Cutter features: oil lubricant port + depth inspection hole

What’s included

• Detailed instructional video with QR code (watching is MANDATORY)

• Billet 6061 cutting fixture — inner + outer pieces (bolt-on jig)

• One 0.125" cutting bit with holder

• One 10-32 set screw for height adjustment

• 10 Viton high-temp O-rings (0.125" thick)

• Patent Pending

Important safety & legal notes — READ CAREFULLY

• WATCHING THE INSTRUCTIONAL VIDEO IS MANDATORY. Follow every step.

• All sales are final once you bolt the cutter onto your heads.

• You are responsible for verifying that your head surface has adequate clearance and that your port and O-ring position will not be interfered with by the jig.

• Once the cutter is bolted to your head you assume full responsibility and liability for any damage. If you follow the step-by-step instructions and check depth frequently, the job is straightforward.

• This tool is intended for experienced DIYers and professionals. If you’re unsure about fitment or procedure, consult a qualified technician before use.