Yes… Here are
"An Even Dozen Things" for EVERYONE to Consider when performing this Task:
(1) ALL Exhaust Manifold and Headers Installation require
PLANNING THINGS OUT… FIRST. Observe and unfasten EVERYTHING THAT STANDS IN THE WAY of getting the Old Exhaust Manifolds OUT and the New Headers IN
...without Beating the Living Hell Out Of The New Stainless Steel Tubes!!!.
(2) DO NOT WASTE TIME WORRYING ABOUT SNAPPING OFF ANY OF THE THREE COLLECTOR PIPE FASTENERS (Xs 2 Sides). You will essentially wind up removing Two Useless, Heavy Cast Iron Boat Anchors when you're done… so Don’t Angst over breaking them ALL off if needs be with a Sturdy Impact Gun.
You want to get them out with the least amount of effort possible…
and THAT is all that matters.
(3) Follow the Written Installation Guide Lines to Install EVERYTHING LOOSELY FIRST and then Gradually Tighten down ALL of the Fasteners on BOTH Banks...Just a Little at a Time.
KEEP YOUR GASKETS ALIGNED AND DO NOT DAMAGE THEM DURING THE INSTALLATION!
(4) While this Shorty Header R&R takes place on a “Roomy” 5.3L LS Header R&R inside of a Silverado, for anyone doing this on a Trailblazer of Envoy and you will NOT have as much room to work in within the Engine Compartment being much tighter spaces. Nevertheless, the Methods and Techniques THIS VOP (Video Original Poster) uses are worth watching:
Part I:
Removing the OEM Exhaust Manifold using Techniques to Avoid Breaking Off any Remaining Fasteners:
Part II:
How to Install the New Stainless Steel Headers Stressing the Need to Pre-Fit them FIRST before the actual installation to ensure that No Additional Flange Drill Outs are Necessary:
(5) Unlike the R&R of the Collector Flange Three Fasteners...you WILL need to be VERY Careful NOT to get anxious and rush through the removal of the Exhaust Manifold Fasteners.
GO SLOWLY AND TAKE YOUR TIME. Avoid Breaking Off the remaining existing Hardware.
The Less of a Mess you make when taking them out… the quicker you will be able to finish.
(6) When the Installation is finished...WIPE AND SPRAY DOWN ALL SHINY HEADER SURFACES WHILE THEY ARE
STONE COLD TO REMOVE OILS, FINGERPRINTS, ADHESIVES, LABELS OR RESIDUAL CLEAR AND SOLID TAPE...
or else their Images will get PERMANENTLY BURNED INTO THE HEADER PIPES!!!
(7) NEVER SPRAY BRAKE-KLEEN OR ANY SOLVENT ONTO ANY HOT ENGINE INCANDESCENT SURFACES OR EXPOSE THAT STUFF TO AN OPEN TORCH OR FLAME…. EVER. Burning These Solvents will instantly create clouds of Phosgene Gas. One Whiff of that awful stuff will be enough to KILL YOU!!! Do NOT Start the Engine until ALL of the Solvent has Evaporated.
(8) Once EVERYTHING is carefully installed and cleaned up… Start the Engine and allow it to Idle for only around 10 Minutes. Then Shut it Down and allow the Headers to Cool Down. When the Engine is Stone Cold… Go around and re-tighten all of the Fasteners on the Engine Head up to 15 Foot Pounds...AND NO MORE. Then Start the Engine and allow it to Idle again for another 15 Minutes. Listen for Leaks, Pops or Weird Noises and Repeat these same Procedures until things Quiet Down.
(9)
NEVER TIGHTEN OR LOOSEN ANY FASTENERS (ESPECIALLY SPARK-PLUGS) EITHER ON THE ENGINE BLOCK OR ON THE ENGINE HEADS IF THE ENGINE IS HOT.
(10) Use Your Head…. Safety First. Using Common Sense and Caution should lead you to
Never be HASTY or Thoughtless. Do NOT Start this Project if you are either Tired or Fatigued. This Work is Physically Demanding and trying to RUSH anything along will only Guarantee that you will make mistakes and
SNAP OFF NEW FASTENERS .
(11) The Engine
will SMOKE a bit after the Header Installation. Only Run the Engine Out of Doors and NEVER in a Closed Up Garage or in any Confined Area. Take care to re-install EVERYTHING you had to previously remove... and ALWAYS
Use the Factory Torque Specs at ALL TIMES.
(12) After the Headers have been firmly Fastened and Heat Cycled, revisit Both sides of the "Y" Pipe Collectors and make sure that their Fasteners are Still Tight.
Avoid Over-Tightening Them. Since they are No Longer Using Studs... you might need to use a Box End Wrench and a Ratchet & Socket Combo on their Upper and Lower portions to ensure they are all tight and resistant to Exhaust Leaks.