These adapters allow you to run a Sidewinder, Viper, and Nytro head with your current YXZ header. No fab is work needed. Bolt on and install your copper gaskets or you have the option to order a new set above. The adapters comes with the exhast studs installed in them as shown in picture. You will need to reuse your flanged nuts. You have the option to buy the mounting hardware that is compatible with your style head.
The Viper/Nytro head uses M8x1.25 mounting bolts
The Sidewinder head uses M9x1.25 mounting bolts
***These will only work with a header that has a movable flange like the stock header. The stud clocking is slightly off from the YXZ head***
