MAC header install questions.

RAGE

New Member
Apr 25, 2004
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Like the title says I have a coulple of questions on a MAC LT header install I am going to help a buddy with on a 04 GT.

I have done header installs on LS1 and LT1 f-bodies but never on a Stang. On the LT1 cars you have to use Fel Pro header gaskets and locking header bolts. On LS1 cars we use stock exhaust gaskets and bolts.

So on a LT MAC header install what gaskets do I need and do I need locking header bolts?

Are front O2 extentions needed?

He is getting the off road Pro Chamber so I think Stangs use MIL eliminators which is the same thing as rear O2 simms right?


Also are exhaust band clamps needed or does the MAC stuff come with hardware?

TIA
 
I think extensions are needed for the rear sensors. MILS are O2 sensor simulators. I'd imagine you can use the stock hardware and I think MAC's products are all flanged with no need for clamps.
~A.C.
 
It not that bad just time consuming. Use the stock gaskets and studs. You will need to remove the intake tube and filter, battery, and starter. Then you can remove the old manifolds. The Mac headers fit really good and the steering shaft is simple to snake through. When you get to the pass side header you will need to remove the motor mounts and jack the motor up a few inches to get it in. Make sure you have a couple extensions (6in, 10in and 24in) on hand and also a couple swivels. Open end ratchet wrenches are your friend :nice:
 
Thanks for the quick responses.

ACSPONY: You are correct, I forgot about MAC's stuff being flanged. On f-bodies when you go with off road pipes you do not hook the rear O2 sensors back up all you need is the sims. You do hook the front O2 sensors back up and due to the bung holes being further down the LT headers you need extentions to make them reach the harness. Why do you need extentions for the rear sensors on a Stang? And if you mean the front sensors do you know if 12, 24, or 36 inch extentions are needed?


03s-281: That is great info and will be really helpfull :nice: . In case he does not check the thread again do you know the answers to what I asked ACSPONY above.
 
RAGE said:
03s-281: That is great info and will be really helpfull :nice: . In case he does not check the thread again do you know the answers to what I asked ACSPONY above.
You should only need 02 extensions for the front sensors. You can get the fron many places online and they are probably 20-50$ but they are simple and plug right in and already come the size you need. I got mine from www.delkperformance.com
 
03-s281 said:
You should only need 02 extensions for the front sensors. You can get the fron many places online and they are probably 20-50$ but they are simple and plug right in and already come the size you need. I got mine from www.delkperformance.com


I looked at that site but could not find O2 sensor extentions. I looked on here http://www.thunderracing.com/ and like for the f-bodies they are simply plug in and come in 3 sizes 12, 24, and 36 inch. On the f-bodies depending on the LT header brand you usually use a 12 inch on the passenger and a 24 inch on the drivers. I know they come ready to just plug in but I don't know what lengths to order.
 
my SLP LTs came with the extensions I needed, but SLP also sells them seperately on their website.

Extentions are used for the front o2 sensors because the o2 sensor is pushed further back with long tube headers. A tune is usually needed at LT install because the car usually has idle problems afterwards. In a tune the timing would be adjusted for the delay of the o2 sensors being further back.
 
christiesledd said:
my SLP LTs came with the extensions I needed, but SLP also sells them seperately on their website.

Extentions are used for the front o2 sensors because the o2 sensor is pushed further back with long tube headers. A tune is usually needed at LT install because the car usually has idle problems afterwards. In a tune the timing would be adjusted for the delay of the o2 sensors being further back.

Yeah SLP sales a install kit for their f-body headers too. Do you know what length they were? That is the same reason we need them for f-bodies. However we do not have to tune for LT headers except for deleting emission codes. Do you really have to tune for just a header install?
 
christiesledd said:
my SLP LTs came with the extensions I needed, but SLP also sells them seperately on their website.

Extentions are used for the front o2 sensors because the o2 sensor is pushed further back with long tube headers. A tune is usually needed at LT install because the car usually has idle problems afterwards. In a tune the timing would be adjusted for the delay of the o2 sensors being further back.
A tune should not be needed after a LT install!! I know 3 or 4 people including myself that had zero idle problems after LT's.
 
RAGE said:
I looked at that site but could not find O2 sensor extentions. I looked on here http://www.thunderracing.com/ and like for the f-bodies they are simply plug in and come in 3 sizes 12, 24, and 36 inch. On the f-bodies depending on the LT header brand you usually use a 12 inch on the passenger and a 24 inch on the drivers. I know they come ready to just plug in but I don't know what lengths to order.
You will have to call Delk to make a order. All they deal with is Mac headers so they will send you the correct size. They both will be equal length.
 
well I guess its not really necessary but I've had idle problems ever since, talked to some people and the person who will be tuning my car on Thursday and they said idle problems can occur :shrug: They're not serious idle problems though.
 
christiesledd said:
well I guess its not really necessary but I've had idle problems ever since, talked to some people and the person who will be tuning my car on Thursday and they said idle problems can occur :shrug: They're not serious idle problems though.
Well, one thing you can notice is a little bog if you just hop in it and take off in the morning when its cold because it takes alittle longer for the 02's to heat up. But that should not effect idle. :nice: