This kit is designed to mount to the original crossmember frame mounting holes on 68-72 SBC V8 trucks and allow the use of side mount "car style" engine mounts. You can also use these to convert your 68-72 6 cyl truck to a SBC (will require drilling). This kit will also enable you to run solid motor mounts in high performance applications. These engine mounts utilize .156 wall DOM tubing and .188 gauge 1018 steel. 2WD applications only.