YOUR CANADIAN MUSTANG WEBSITE
Header Install (94-95 )
OK, here it goes, this is an overview on how to install shorty headers into a 94-95 GT. I've broken it down to 12 steps. It should take you the better part of the day if it's your first time.
1) First start off by making sure your gaskets properly line up before popping the hood! I had to enlarge a couple of holes and trim the interior of a couple of the ports on my set. Now pop the hood and disconnect the neg. battery terminal.
2) Now soak down the nuts which hold the headers to the H-pipe with WD-40 or something similar and let sit for about 20 minutes. A good thing to do during this time would be to remove the whole air cleaner assembly. Disconnect the hose from the TB and loosen the bolt on the fender which holds the filter casing so that it can be removed. Disconnect the wiring harnesses, and vacuum tube. Pull out the unit.
3) Now go back to those H-pipe nuts and take them off. It would make life a lot easier if you had an impact gun for this but I did mine with just hand tools.
4) Make a diagram of your engine, so that you'll remember where each plug wire will go. This came in very handy for me and saved a lot of time! Number the cylinders 1-4 on the passenger side and as you pull each plug wire put masking tape on the end and number it according to the cylinder in which it came from according to your diagram. Repeat the process for the other side using numbers 5-8. You don't have to remove the wires from the cap!
5) Now it's time to remove your spark plugs. When removing them use the same numbering system you used for the plug wires. Remember to clean out the cavity that the plug is in with compressed air or a small tube and lung power. This prevents any dirt/ debris from falling into the cylinder.
6) Starting with the passenger header loosen all bolts, then go back and remove them from the center out. Pull the header free and remove. Use some gasket remover and a putty knife to remove any residue left by the header gasket.
7) Drop in the new header making sure that the studs of the header are correctly through the ring on the H-pipe. It might help to have someone under the car to help guide the header into place. While holding the gasket and header in place, screw in the rearmost and front most header bolts to support the header and finish up with the rest. Make sure to connect the small bracket at the back of the engine which was attached to the factory header. Get under the car and screw the nuts onto the studs finger tight.
8) You'll notice that the driver's side is a little tighter but you don't have to jack the engine! Removal is the same as the passenger's side with the exception of the dipstick. You'll disconnect the support bracket when removing the header bolts. When this is done, go underneath the car and pull it out of the block and snake free of the car through the top. You will most likely have to notch the bracket to fit against the header. Do this while you have both out of the car. Make sure to reinstall the dipstick!
9) Almost done. Now tighten all header bolts on both headers to proper specs. You may need a thin wall socket or a wrench. Get under the car for the last time and tighten the H-pipe to the headers. Get out the diagram which you used to tag the spark plugs and wires. Install them in their previous locations following the diagram. Connect the battery.
10) Start-r-up! Check for exhaust leaks. If there's no leaks then install the air filter assembly and hookups. Disconnect the battery before doing this and reconnect after the install.
11) Now with everything reconnected and tightened take your car out for a break in period of about 10 minutes. Let the car slowly come to operating temp. You will likely see some smoke from underneath the hood. Don't worry, it's just the headers breaking in. I installed Macs and that HTS coating really smoked like crazy! At first I thought I had an engine fire!
12) Last step. Let the engine cool for and hour and then retighten all header bolts and H-pipe connections. Do this again after about a week of driving and then after about a month. Sounds like a lot but having those headers heat and cool, thus expanding and contracting will keep loosening them until they really get broken in. After that you should check them twice a yr. and tighten if necessary. If you want, I here people say that the locking header bolts work great. You'll notice that the exhaust sound is probably a little deeper and mellow now.
Have fun with the extra few horses you picked up!!!
Written by: Chris Dyck