HOW TO INSTALL JBA CAT4WORD HEADERS

COMMENTS: These instructions are written for a 5.4L engine (Header part#1679S) but there should be no major difference for the 4.6L applications (#1677S).  These instructions cover the best way I found to install the headers however there a few different techniques and tools that can be used and still work.  Some of the text for these instructions came from JBA's online instructions.  JBA says that any shadetree mechanic with the right tools, some general mechanical ability/experience, and some spare time should be able to tackle the task of installing these headers.  If you doubt you'll be able to complete it when you start it, it may be better to consult a professional mechanic, better to do it now than to get stuck half-way through the installation after all.

PREPARATION FOR INSTALL:      If you are prepared for the installation you will save a lot of time when doing the actual installation. In the days leading up to the header installation you can work on making the nuts and bolts easier to remove. Once the engine has cooled and you won't be driving it anymore for the night, spray some WD-40 or other spray-on lubricant on all bolts that will be removed during header installation.  This includes the 8 bolts per exhaust manifold attaching the old header to the block, the EGR valve connector (the 1 1/4" connector attached to the drivers side header), and the bolts connecting the stock manifolds to the exhaust.  This will make loosening and removing the bolts much easier on the day of the install and will help prevent snapping off bolts. If you plan on removing the front driveshaft to assist with installation (4-wheel drive only), prior to parking the vehicle be sure to engage four-wheel drive, otherwise you will not be able to free the bolts connecting the driveshaft to the flange.

TOOLS NEEDED FOR INSTALL: 15mm and 1/2” deep sockets, 7/32”, 5mm and 13mm sockets, as well as ¼”, 3/8”, and ½” socket wrenches, with a variety of 3”, 6”, and 9” extensions for all sizes. 1 1/4" wrench (modified accordingly) for EGR Valve, 1/2” and 13mm wrenches, as well as stubby wrenches if available. For some bolts, ratcheting wrenches made the job about a hundred times easier. A body trim panel remover (or pliers) for removing body bolts in the fender well will make the fender well job much easier.  You may find it easier to also have an air ratchet and impact gun nearby.  You will also need a jack and at least two jackstands to support the vehicle. Below you will find a picture of the tools I “invented” for this installation.

Tools that were invented for this installation that made it much easier

1.    Once ready for the actual installation, park the truck on a level surface and allow the engine to cool, once again spray a small amount of WD-40 on the bolts to be removed.  Do not attempt to work on a hot engine.  Heat causes metal to expand and makes removal of fasteners difficult at best.  Disconnect the battery cables from the battery.

2.    Jack up the front of the vehicle and support with jackstands.  As always its a good safety precaution to block the tires to prevent the vehicle from rolling off the jack stands.  Then unbolt and remove the front wheels.

3.    From underneath the vehicle, loosen the bolts connecting the exhaust system to the exhaust manifolds using a 15mm deep socket.  At this point you may also want to disconnect your driveshaft (for 4-wheel drive versions) and let it dangle.  JBA states the installation is easier if you disconnect the front driveshaft by removing the 4 bolts on the flange, but during out installation we didn't remove it and we had no problems.  If you wish to remove the driveshaft, you will need a 12mm 12-point socket, no other socket will work.  These don't come standard in many tool sets so a trip to the hardware store may be required. Pry the exhaust system back about 1/2” to gain work space.  We also found it more convenient pry the catalytic convertors down, but loosening the bolt attaching the pipes just past the catalytic converters to the exhaust, and rotating downwards.

Removing the 7/32” bolts attaching the wheel well.

4. JBA says it isn't required that you remove the inner fender wells, but I don't see how you can do the install without removing them (besides they don't take too long to remove and it makes the install much easier).  To remove the fender wells simply unscrew all the sheet metal screws (using a 7/32" socket) and fasteners attaching it to the fender and frame and the fender well will drop out.  You will also have to pry off any of the "Christmas tree body bolts" that connect it to the body, as well as disconnecting some electrical wires that may be "clamped" the fender well (on some models).

EGR Valve components

5.    Working through the wheel well, on the driver’s side, loosen the EGR tube from the old manifold. The EGR tube is the tube that connects the headers to your EGR valve. As seen in the above picture, you will have to loosen part A from part B. Part B will be removed later, once the manifold is off the vehicle.  This is a 1 1/4" bolt and may be on quite tight.  I found the best way to remove this is to make a custom tool for it by grinding away at a standard 1 1/4" wrench so I could slip it over the EGR tube and then loosen the EGR bolt (see picture).

6.    Still on the drivers side, remove the nuts attaching the old exhaust manifold to the head.  Remove the manifold and the manifold gaskets.  JBA calls for you to remove the studs attaching the old manifold to the head, but we found when working on it that the studs on the drivers side can actually be reused, so we simply left them.  If you prefer to use JBA's supplied bolts, you can remove these studs (B in the below picture) with a 5mm socket and a 1/4" socket wrench.

Drivers side head with manifold removed. (A) dipstick bolt, (B) manifold stud, (C) EGR tube and (D) exhaust outlet.

7.    Remove the dipstick. It has a separate mounting bolt on the head (see A in above picture) and uses an O-ring seal at the bottom.  This can be pried loose slightly with a flat head screwdriver and pulled out from the engine compartment.

8.    On the passenger side, again working through the wheelwell, remove the nuts attaching the manifold to the head and disconnect it from the exhaust, then remove the header.  Due to space restrictions on the passenger side, the 5mm studs will have to be removed in order to position the header.  In our installation, we found the two studs towards the front of the engine can be reinstalled once the header is in place, but due to curving of pipes, the rest will need to be replaced with the supplied 13mm bolts.

9.    Using a gasket scraper or carb and choke cleaner with a toothbrush or clean rag, remove all carbon deposits and high spots from head surface, being careful not to gouge the aluminum heads.

10.    Remove the EGR fitting (part A in the picture of the EGR connector) from the factory header and install it on the new header. (this item can be extremely tight on the stock manifold and a breaker bar, possibly with an extension, will be needed. For our installation, we had to clamp the old manifold tightly into a vise and use a breaker bar with a pipe for extension to remove it.

Installing RTV on the header flare, as well as the exhaust pipe flare”

11.       Apply a small amount of Hi-temp RTV (sensor safe) to the exhaust pipe flare on the drivers side.  For those unfamiliar with RTV, it is a gasket maker.  The best product out there can be found at autozone or any other auto parts supplier and is made by permatex.  For a link to what you are looking for, see there web site.  Once RTV is applied, then install the driver side header from underneath the vehicle.  Some twisting and wiggling of the header is necessary to get the header in place.  Before inserting over the bolts, apply a small amount of thread lock to the threads of the bolts and ensure that the gasket is installed between the header and the head, and finger tighten a few nuts on.  If you chose to remove the studs attached to the head in step 6, you need to insert the new bolts at this point and finger tighten them.  Be careful not to cross thread, as a damaged head can be VERY expensive! The EGR tube must now be loosened at the EGR valve (from the top) and attached to the fitting on the header.  Re-install the dipstick.  Tighten the EGR tube (this will take some work due to the body being in the way, as well as restricted movement of a wrench, but it is possible to do!).

12.       Follow the same procedures for the passenger side, except install the passenger side header through the wheelwell.  Same as in step 11, make sure to apply a small amount of thread lock to the threads and make sure the gasket is installed, and finger-tighten a few bolts to hold the header into place.

13.       Re-connect the exhaust system to the new headers using the hardware provided. (Re-connect drive shaft if you disconnected it earlier)

Using my homemade stubby wrench to tighten the passenger side bolts

14.    Once the header is in place with gasket installed and connected to the exhaust pipe, finger tighten all nuts attaching the header to the head. Once all bolts/nuts are finger tightened, use a socket wrench to tighten evenly. At this stage, do not torque any bolts extremely tightly until all are evenly tight or it may damage the gasket. The best technique to use is to torque down each bolt slightly, then once each is torqued down slightly with the socket, then go back and tighten each one more, then finally torque to completion.  Keeping it even will prevent the gasket from getting smashed and damaged, requiring reinstallation and possibly purchasing of new gaskets.

15.       Re-install the inner wheel wells (if removed).  Check to ensure that there is adequate clearance on all brake lines, wire looms, a/c lines, etc.  On 4.6L models, it is recommended that you remove the passenger side wheel well flap.

16.       Re-install the front wheels and torque to factory specs. (100 ft. pounds)

15.       Reconnect the battery.

16.       Re-check everything!

17.       Start the engine, check for leaks and test drive.  Then let engine cool and then re-torque the header bolts.

18.       It is a good idea to occasionally check and retighten the header bolts.