Kooks Header Installation


Header installation is a little bit of work on these things. The passenger side being the tightest to snake the header into place. Removing the washer reservoir and coolant tank and roping the AC dryer out of the way gives you more than enough room to install the header from the top. Removing dipstick and heater hoses from front of motor is required. See figure 2.

This writeup is not meant to replace the header manufacturers instructions but just supplement them with some tips and pictures. So all warnings about jack stands, disconnecting battery cable, etc still apply.

You can take a look at the stock manifolds in Figure 1 and see the poor match to the heads by looking at the carbon line. I would think if someone was bored and wanted to just do a gasket match and add a high flow Y pipe the stock system would not be too bad.

The Kooks instructions tell you to jack up the transmission and remove the tranny crossmount and front crossmount. You can then remove the Y-pipe and then reinstall the rear crossmount. These Y pipes can be hard to remove even after the rear cross member is out. Personally, I would cut the Y pipe as shown in figure 3 and not worry about removing the cross member. If you cut it in a straight section its an easy fix if you decide to demod later. This will save you a fair amount of time if you are doing a driveway install.

Note: Andy at ADM has a good tip for removing the Y pipe. Use a cheap ratchet tie down strap to pull the left and right pipes together and drop it out from inside the frame.

The Kooks instructions (available here) tell you to remove motor mounts bolts, jack up the motor and push the transmission tail shaft towards the drivers side to install the passenger side header. I was able to do it without moving the transmission. I just installed the header until it wouldn't go any further and give it one light tap with a rubber mallet and it fell right in. See figure 4.

The motor mounts are complex and its hard to figure out what bolts to remove. The bolts are both on the bottom and thread up into the lower part of mount. AWD trucks will find it a challenge to get at bolts because of the drive shafts.

The drivers side header installs from the bottom and is pretty simple. If you are AWD you will need to unbolt the front of drive shaft where it attaches to the front differential and push to one side. It's always a good idea to tape the universal joint caps in place so you don't knock the caps off.

Tip: You might want to install the front o2 sensors while the collectors of the headers are hanging low before you bolt them up to heads. If you don't it may be hard to install and tighten the sensors.

Once the headers are bolted to the heads you can reinstall the drive shaft (AWD), front cross member and install the Y pipe. Install the rear o2 sensors if used and connect the wiring.

Before putting the engine compartment back together I would install the plugs and wires while you have the extra room.

Reinstall the coolant overflow tank, AC dryer and reattach heater hoses, AC brackets, dip stick and anything else removed to provide clearance. Reinstall washer fluid tank and intake system.

Reconnect battery and refill coolant system.

It is highly recommended you heat cycle the truck a couple times and then re tighten all exhaust system bolts.

Once running I did a couple scans and had to tweak my tune to get AFR back in check.