Mac headers

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gregandmike

New Member

Sep 22, 2009

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massachusetts

Nov 9, 2009

#1

• Nov 9, 2009

• #1

I bought a used set of Mac Shorty headers for my 87 mustang 5.0. I am having a problem installing them. Most of the bolts will go in and the others will not. It appears that the holes in the headers are slightly off from the bolt holes in the heads.. Any ideas as to what the problem could be and is there a fix, besides getting new headers ? Thanks

 

rbonella

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Dec 15, 2008

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@ home

Nov 9, 2009

#2

• Nov 9, 2009

• #2

what heads are you running? Hopefully not the gt40P heads.

 

tannerc91gt

This last 25% is foreign territory at this point

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Nov 9, 2009

#3

• Nov 9, 2009

• #3

I've got mac shorties on my car, have had 0 problems.

 

stykthyn

I want to measure mine. It doesn't look that tall.

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Nov 9, 2009

#4

• Nov 9, 2009

• #4

tannerc91gt said:

I've got mac shorties on my car, have had 0 problems.

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thats real helpful

MAC headers are notorious for this. its because of the individual header flanges. they warp due to heating as they are used and once taken off are a ROYAL PITA to put back on. for this reason I urge anyone to skip these and go with a single header flange like the BBK headers use. If you can try heating the primaries with a torch and see if you cant move them over the necessary distance to put the header bolts in.

IMHO put the stockers back on if you got them selll the MACs and get a header with a single flange. I picked up my BBK shorties with the ceramic coating for 125 used so there are good deals out there. just keep an eye out.

 

tannerc91gt

This last 25% is foreign territory at this point

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Nov 29, 1999

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Nov 9, 2009

#5

• Nov 9, 2009

• #5

It was meant to be helpful in a "all mac headers don't suck" sort of way. Also had mine off multiple times and haven't had an issue. Sorry if it wasn't helpful.

 

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gregandmike

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Sep 22, 2009

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massachusetts

Nov 9, 2009

#6

• Nov 9, 2009

• #6

Thanks

Thanks for your responses. I believe the heads are stock. Maybe I will try to heat them up. Thanks....

 

8

89fiveliter

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Nov 5, 2009

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Nov 9, 2009

#7

• Nov 9, 2009

• #7

Ive installed MAC headers on all three of my fox body's. The Longtubes are a PITA usually, but not always. had an 84 that I about jacked straight up on the bumper that had the headers go in no problem. A 92lx AT with equal lengths that was very easy and last a 89 GT with a 5 speed that about made me wanna buy BBK's! I just got as many bolts as i could in that would go in. Then have somebody pull on the header that your having problems aligning until the holes line up while you put the bolt in! Pry bars, whatever works. I cant imagine they are too far off. Good luck!

 

tmoss

Gettin Wired

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Jun 28, 2001

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Nov 9, 2009

#8

• Nov 9, 2009

• #8

I took a carbide bit an slotted the bolt holes so that putting them on is much easier. Did that and then sent them to Jet-Hot for coating.

 

stykthyn

I want to measure mine. It doesn't look that tall.

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Nov 9, 2009

#9

• Nov 9, 2009

• #9

tmoss said:

I took a carbide bit an slotted the bolt holes so that putting them on is much easier. Did that and then sent them to Jet-Hot for coating.

Click to expand...

now thats a hell of an idea

Posted via Mobile Device

 

blackened88lx

Active Member

Aug 9, 2006

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Nov 9, 2009

#10

• Nov 9, 2009

• #10

My mac long tubes have been around the block a few times and were a piece of cake to put on. Everyone loves to bash mac exhaust products but me or my buddies have never had an issue. All it takes is a little common sense and ingenuity.

tmoss said:

I took a carbide bit an slotted the bolt holes so that putting them on is much easier. Did that and then sent them to Jet-Hot for coating.

Click to expand...

Exactly what I was going to suggest.

 

Maryland Stang

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Aug 21, 2002

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Nov 10, 2009

#11

• Nov 10, 2009

• #11

rbonella said:

what heads are you running? Hopefully not the gt40P heads.

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Yeah. What's that have to do with the headers fitting? Any header that will fit all of the rest of the small block Ford heads will fit the Ps. You may have an issue with the plugs and wires but the headers will bolt right up. The GT-40P is considered by many to be one the best cast iron heads that Ford ever made.