How do I install headers on my truck?
Well, you're in luck because I just replaced mine and I took some photos. Total install time was about 4 hours, but I'm sure some of you gear-heads could do it faster.
1. Unbolt exhaust manifolds. Easier said than done. Most of your time will be doing this step, so be prepared. Mark your sparkplug wires prior to removing them. This is also a good time to replace your sparkplugs since it can often be a difficult chore when headers are in place. Not all headers are equal mind you (as I quickly found out). The new Edelbrock headers I installed in place of the Flowtech ones had several design elements that make life easier: recessed area for wrenches, full length flat header flanges, notched outer bolts for easy removal/installation, slightly larger area for easy spark plug removal/installation. Together, these features made for easy installation.
Passenger side is pretty easy. Dipstick pulls right out and just one header bolt is securing it. 6 header bolts secure the exhaust manifold to the cylinder head. There are three bolts at the collector that need to be removed. Driver side has a spacer at the front of the engine near cylinder #1 that can cause some problems. It may be necessary to remove the bracket that attaches to the power steering pump. Depending on the amount of rust present, it would be a good idea to use a good penetrant spray available at your local automotive store a few days before tackling this (with a few applications on the nuts/bolts) to loosen things up a bit.
Some of you might be asking yourself why I'm taking my old headers off and installing new headers? Well, the pictorial below explains why.
Larger collector opening (minor issue) and larger space between header flange and header tubes to assist spark plug removal once the header is installed.
Header leaks!! See all the carbon deposits on the old header.
Perfectly flat flange. Any aftermarket gasket can be used.
Not a flat flange. For some reason, Flowtech decided to not completely flatten out the welds on the inner side of the header flange. The result? Very little material is available to seal the header. Change the stock heads to aftermarket ones like I have and you have a recipe for disaster.
Close-up of raised welds
Passenger-side header removed
Close-up of head surface showing poor fit. Even if I match gaskets to the header, the larger ports of my aftermarket heads leave little room for the gasket to properly seal the two surfaces.
2. Modify gaskets for easy installation. Essentially notch the area below the outer bolt holes of the header gasket, as shown below. Note that some aftermarket gaskets (ie. Felpro) will come with this modification already performed.
3. Install new headers. Start by putting the two end bolts on with the header loosely attached as illustrated below.
4. Drop modified header gasket over end bolts for a perfect fit everytime. Now the holes will line right up and you can insert the other header bolts. Leave everything slightly loose to allow for some movement when attaching the y-pipe to the collectors.
Want to make life easier for you. Get a set of ratchet wrenches that have adjustable wrench head angles. Way easier.
5. Loosely tighten collector bolts. Have your bolts already installed as shown below when you install your header. It can be difficult to get the bolts into the holes once the header is installed. This is a huge time-saving step and you will thank me many times over for suggesting it.
6. Tighten all bolts. Torque header bolts to 30 ft/lbs. Do not over-torque. I can't repeat this enough as over-torquing can warp the header flange and you'll get header leaks galore no matter how tight you tighten the bolts. Torque sequence should be inner to outer in a clockwise fashion.
Use a similar technique to tighten collector bolts. Go slow and tighten each bolt til you start to feel resistance. Then use a 3-stage torque sequence: 20, 50, 100 ft-lbs. This ensure even contact to prevent misalignment and leaks.
7. Reconnect sparkplug wires and other connectors and that's it, you're done.
Need more instructions? Here is a link to the instruction set from Edelbrock:
http://store.summitracing.com/instructions.asp?File=edl%2D6566%2Dheaderfor88%2D9 5pu92%2D95su%2Epdf