How to Install Stainless Works 1-7/8 in. Headers w/ Off-Road Y-Pipe - Factory Connect on your Sierra

Thanks for purchasing Stainless Works Muscleflow Headers for your 07 -15 Chevy Silverado 1500 V8 truck. We have gone to great lengths to make sure that our exhaust systems fit and sound great. Please follow these steps to ensure that your installation goes as planned.

Note: these systems have been designed to fit a crew cab standard box truck, which has a 153" wheelbase and 78.87" long box. as well as the shorter crew cab with short box (143.5" wb and 69.33" box) or double cab with standard box (143.5" wb and 78.87" box) trucks. although not fully tested the factory connect headers (with a y-pipe) may fit other wheelbase trucks.

1. Stainless Works recommends the use of Hi-Temp RTV sensor safe silicon gasket maker as an option to or in conjunction with the use of factory gaskets. The recommended Oxygen Sensor Safe RTV is either Valco All-in-One Aluminum or Permatex Copper P/N 101BR available at NAPA, Autozone and other retailers.

2. Disconnect the battery before starting work on the exhaust system for your vehicle. Reconnect the battery when the job is completed.

3. Your exhaust system can be installed by a weekend warrior but the use of a lift is recommended for ease of installation. If using a jack, the vehicle must be placed on a level hard surface and jack stands are required for safety reasons.

4. You will assemble the components together as specified below, but only snug the clamps as you move along from front to back. When placing the X-pipe or Y-pipe into position, make certain that you push it fully forward and level it with the vehicle. After aligning all the components in the vehicle, you will tighten all the clamps working from front to back of the vehicle.

5. Raise and support the vehicle.

6. Disconnect the battery.

7. Loosen the clamp at factory stepped ball connection point.

8. Disconnect and remove all (4) 02 sensors.

9. Support the transmission and remove (2) 12mm nuts, transmission to cross member mount.

10. Remove (4) 14mm nuts and bolts in cross member and remove the cross member.

11. Remove (6) 10mm nuts (3 per side), from factory Y-pipe to exhaust manifolds and remove Y-pipe. Then re-install cross member.

12. Remove (4) 8mm bolts in front drive shaft to front axle U-joint and move the drive shaft towards the transmission.

13. Remove vent hoses from the right and left valve covers and remove plastic coil covers.

14. Remove 8 spark plugs and wires.

15. Remove dipstick (1) 6mm bolt.

16. Remove (10) 8mm bolts (5 per side) from exhaust manifolds and remove manifolds.

17. Using RTV, seal and install the headers (10) 8mm bolts (5 per side).

18. Install right and left lead pipes either catted or off-road using (2) 3" clamps.

19. Install either X-pipe (Performance Connect) or Y-pipe (Factory Connect) depending which system you purchased.

20. Tighten and adjust from front to back.

21. Re-install 02 sensors (Left rear requires the supplied extension) others may need to be removed from clips that hold them to the frame (to be extended to fit the longer lengths required).

22. Re-install all components that were removed previously.

23. Be sure to have adequate clearance around all wires, hoses and lines. If anything is in contact with the exhaust system, it will melt. Make sure to have at least 1/2" of clearance and wrap any suspect areas with DEI thermal barrier wrap.

24. After double checking for clearance and making sure all lines, wires and hoses are secured, drive the car for 10-20 miles and re-check all clamps and clearances. Your system may be tack welded at the joints/ clamps to reduce shifting of the system during heating and cooling cycles. Make certain to disconnect the battery before performing any welding.