3/6/04 installing shorty headers 92gt

racer_inboston

Founding Member
Feb 2, 2002
310
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16
boston, ma
Hey gang,
this saturday I'm going to be replacing my stock exhaust manifolds with shorty macs.
Any tips as to this procedure woul dbe helpfull, since i have never done this and i dont know if i will run into any obstacles. I know the drivers side is ok to get at, but i can see that the pass side will be a pain in the balls!
tks
 
racer_inboston said:
Hey gang,
this saturday I'm going to be replacing my stock exhaust manifolds with shorty macs.
Any tips as to this procedure woul dbe helpfull, since i have never done this and i dont know if i will run into any obstacles. I know the drivers side is ok to get at, but i can see that the pass side will be a pain in the balls!
tks

passenger side isnt as bad as people say. the dipstick on the driver's side is probably the most annoyingest part. just take out the spark plugs on the passengerside, but make sure to remember where the spark plug wires go. take off your h-pipe or whatever you have so your header studs dont run into them. all in all, if it's your first time it might take an hour or so. make sure to use locktite on the bolts too.
 
I would not use locktite on the header studs, if you do, they may never come loose next time the H pipe needs to be dropped for other maintenance. Use Never Seeze instead, the bolts will not back off, and they will not seize up either.

If you haven't already bought the MAC pipes, don't. MAC quality leaves a lot to be desired. :notnice: The headers with individual flanges warp when they get hot and are very difficult to re-install if you have to remove them. Even if you get all the bolts back in, they are prone to exhaust leaks.
 
racer_inboston said:
Hey gang,
this saturday I'm going to be replacing my stock exhaust manifolds with shorty macs.
Any tips as to this procedure woul dbe helpfull, since i have never done this and i dont know if i will run into any obstacles. I know the drivers side is ok to get at, but i can see that the pass side will be a pain in the balls!
tks
uh didn't it come stock w/ headers? I'm not questioning your choice for an aftermarket header, but I believe it should have stock headers, not manifolds
 
TO:theuser,
Yes it has stock headers, but isnt an exhaust manifold a header? i always thought it was, even when i went to buy the gaskets i asked for "exhaust manifold gaskets" and they gave me the header gaSKETS.

TO:JRICHKER,
tHESE HEADERS I PURCHASED FOR $50 from a friend, he said they were mac. they did come off a 5.0 87-93. they have one complete flange not individual flanges per tube. So are they not mac headers? the only thing they have stamped is a 6 digit #117-701, what ever that means. who makes this header just so i know?
 
racer_inboston said:
TO:theuser,
Yes it has stock headers, but isnt an exhaust manifold a header? i always thought it was, even when i went to buy the gaskets i asked for "exhaust manifold gaskets" and they gave me the header gaSKETS.
Headers have a primary tube coming from each cyclinder individually leading to the collector; Manifolds, I believe, typically exit one cyclinder and go to the next sequentially for all cyclinders on that side and then to the collector. Basically, Headers let the motor breathe better by letting the exhaust from each cyclinder exit it's own tube instead of being mixed with the other exhaust. Gaskets would probably be the same for either since there's not really a difference, they're just exhaust gaskets.
 
Use NeverSieze as JRichker suggests - on all the header/exhaust related bolts. Take your time especially during the fitment of the header itself - be sure that all the bolts go right in and you can do the initial tightening by hand. If you find you're having to force bolts through the holes to get them started, or pry on the header to get them to line up, put your stock ones back on, sell the Macs again, and buy a better quality header (I think FRPP is the best value). Don't know what your other mods are - but I wouldn't expect miracles with the shorties. Unless the engine's making more than about 270-280 HP, the stock manifolds aren't a restriction even though they look pinched. I dyno'd before and after with a very mild build, and there was no change with the shorties - well, we actually lost a HP or 2.

Exhaust manifold, headers -- it's a distinction without a difference. The term 'manifold' came from the days past when most cars had very poor flowing cast iron devices installed by the factory for allowing the exhaust to exit the head and get into the rest of the exhaust system. 'Headers' were generally mild steel tubular affairs, and so exhaust manifold came to refer to the bulky cast iron things, and headers came to refer to the tubular things. Well, the stock HO 'exhaust manifolds' aren't cast iron, and they are tubular, but they came that way from the factory - so which term would you like to use? Again - a distinction without a difference in my mind.
 
The Neversieze is great but spend the 40 bucks on Stage8 locking header bolts. They will make your long term header experiance soo much better. You can get them from Jegs, Summit and the such. Good luck. It is not that hard. And remeber have fun, that is what Mustangs are for.
 
As for locking header bolts - in almost 35 years of modding cars and motorcycles, I've never used a set, and never had a problem with bolts coming loose or leaking gaskets. Use a high quality header, bolt and gasket, retorque them after the first heat cycle, and they should stay tight. At least mine all have. Even on the race cars that got used really hard. I don't know of any factory car that uses locking bolts, nor that requires you to come back in 500 miles after you bought the car for a header-bolt retorque. I don't believe they're a requirement if things are done properly, but, whatever pumps a little sunshine up your skirt.
 
Both Mac and BBK make or have made headers of both styles - individual flanges, and the single flange. The single flange keeps the spacing between individual primary tubes correct. The individual flanges can allow them to move around - this is an issue even on the stock HO header.
 
Ok guys, DONE!!! perfect fitment (single flange for all tubes) had to use really small bolts since I barely had space to fit a socket, and had to use a wrench in some of the bolts. The only bad hting that occured was, that the lil skinny hoses (beige and black color that snap in and sit right next to the throttle body) 2 of them broke. I where do i get these lil skinny hoses?
 
racer_inboston said:
Ok guys, DONE!!! perfect fitment (single flange for all tubes) had to use really small bolts since I barely had space to fit a socket, and had to use a wrench in some of the bolts. The only bad hting that occured was, that the lil skinny hoses (beige and black color that snap in and sit right next to the throttle body) 2 of them broke. I where do i get these lil skinny hoses?

Get some small pieces of rubber vacuum hose and patch them up -- will work perfectly...just make sure the size you get is a good tight fit.