Vintage Mustang Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
124 Posts
Discussion Starter #1
I’ve been installing some Mac ceramic coated long tube headers on my 70 coupe. Passenger side I thought was going to be a real pita ended up going not so bad. The driver side how ever has been nothing but torture. I’ve got all the bolts in except one the very far rear bolt won’t go in. You can see with a mirror that the hole doesn’t line up 100%. I’ve tried everything from prying to up, a strap to pull up on it doesn’t work. I haven’t consulted Mac yet on this problem was just hoping magically it would go in. These headers have a lot of ground clearance and you don’t have to do a drop on the steering. But what Im having a hell of a time with also is the Automatic Shifter Linkage Rod, I can’t not find for the life of me do they make this in a cable or is there only a rod for the c4 trans? Was hoping to get this exhaust done soon but it sure as heck doesn’t seem like it’s going to.
 

·
Registered
Joined
·
183 Posts
have you tried taking the bolts out and re-started by threading the rear one first? Also, how tight are you threading the bolts? Make sure to leave some play in it. Weird stuff happens sometime.
 

·
Banned
Joined
·
2,711 Posts
How far off is the rear bolt hole? I'm sure it wouldn't be fun to do because you'd have to take the header out but could you elongate the rear hole a bit on the header flange itself to make it fit? Typically the issues with exhaust come from the drivers side because you have to worry about fitment issues with steering/transmission/clutch components, z-bar's and so on, even though you said you have an automatic... but it typically gets even more complicated especially when you are using long tube headers. I would contact MAC first and see if they have a solution and double check the part number for the headers that you have as well before you do any drilling but if it's only slightly off and these are the headers you want to use? Have at it, especially if you can't ship them back now since they're used.
 

·
Registered
Joined
·
124 Posts
Discussion Starter #4
354171A5-172D-4560-A7DA-760DDE747026.jpg What? Removing all the bolts then rethreading
Them from end to end? This headers are individual and not a one piece like I had before which honestly is the biggest pain in the ***
 

·
Registered
Joined
·
183 Posts
ahh...nevermind then. didn't realize those don't have a solid flange across all the tubes.
 

·
Registered
Joined
·
124 Posts
Discussion Starter #6
How far off is the rear bolt hole? I'm sure it wouldn't be fun to do because you'd have to take the header out but could you elongate the rear hole a bit on the header flange itself to make it fit? Typically the issues with exhaust come from the drivers side because you have to worry about fitment issues with steering/transmission/clutch components, z-bar's and so on, even though you said you have an automatic... but it typically gets even more complicated especially when you are using long tube headers. I would contact MAC first and see if they have a solution and double check the part number for the headers that you have as well before you do any drilling but if it's only slightly off and these are the headers you want to use? Have at it, especially if you can't ship them back now since they're used.
Yeah I agree, I was honestly going to drill it out tonight but decided against it and posted on forum instead. I would say it off by an 8th of an inch. I had another one like that but was able to pull up on it and thread the bolt in. I’ll have to try calling tomorrow see what they think could it be casted wrong of coarse but idk.
 

·
Registered
Joined
·
7,776 Posts
View attachment 672473 What? Removing all the bolts then rethreading

Them from end to end? This headers are individual and not a one piece like I had before which honestly is the biggest pain in the ***


If you start both ends and work in, it should make it much easier. I have those bolted up to 289 heads and they are a little more work to get them on, but it’s worth it!


Sent from my Sarcastic phone
 

·
Registered
Joined
·
124 Posts
Discussion Starter #8
If you start both ends and work in, it should make it much easier. I have those bolted up to 289 heads and they are a little more work to get them on, but it’s worth it!


Sent from my Sarcastic phone
So you started the outsides and worked your way to the middle? We’re any of the holes way off when you were installing them or they seemed to go in not too bad? Just seemed while Doing driver side few especially the inside ones were not lining up right, and I assume you have a stick which wouldn’t be an issue with this stupid trans rod.
 

·
Registered
Joined
·
7,776 Posts
So you started the outsides and worked your way to the middle? We’re any of the holes way off when you were installing them or they seemed to go in not too bad? Just seemed while Doing driver side few especially the inside ones were not lining up right, and I assume you have a stick which wouldn’t be an issue with this stupid trans rod.


I’ve always started the two outside bolts, them hang the gasket, then start the rest. Leave them all with just a few threads started so you have the most wiggle room. Yes, I do have a toploader, but twisting the equalizer bar in is an act of a contortionist


Sent from my Sarcastic phone
 

·
Registered
Joined
·
124 Posts
Discussion Starter #10
I’ve always started the two outside bolts, them hang the gasket, then start the rest. Leave them all with just a few threads started so you have the most wiggle room. Yes, I do have a toploader, but twisting the equalizer bar in is an act of a contortionist


Sent from my Sarcastic phone
Yeah I was afraid of that, guess I’ll start the bending, can’t be too hard. I bend pipe for a living 👍, I’ll takr your advice and back then almost all the way out see if that helps for any reason.
 

·
Registered
Joined
·
8,974 Posts
If you want some real joy, try installing a set of Pontiac headers....

Anytime I had an issue with a specific bolt, I would start over and put that one in first, just like has been suggested. Once you have the ends in and the gasket hung, you can work your way in. You can always try persuading the tubes around a bit with a pry bar wrapped in a rag to protect the coating.

Regarding the shifter linkage - if it's the backdrive rod going to the steering column from the transmission, many headers require you to remove that rod for clearance.
 

·
Registered
Joined
·
19,948 Posts
I’ve got MAC headers on GT40P heads. Take the left side out and put a straight edge on the 3 tubes. You’ll probably find one of the tweaked. I ran into the same issue but I blame that on myself. I had one tube touching the frame rail and that to slightly flatten the side of the tube. The banging was just enough to throw the tube slightly off. I corrected the issue and the header went right in

 

·
Registered
Joined
·
4,695 Posts
I’ve got MAC headers on GT40P heads. Take the left side out and put a straight edge on the 3 tubes. You’ll probably find one of the tweaked. I ran into the same issue but I blame that on myself. I had one tube touching the frame rail and that to slightly flatten the side of the tube. The banging was just enough to throw the tube slightly off. I corrected the issue and the header went right in

Dang that's close...everywhere.

Allen
 

·
Registered
Joined
·
124 Posts
Discussion Starter #14
If you want some real joy, try installing a set of Pontiac headers....

Anytime I had an issue with a specific bolt, I would start over and put that one in first, just like has been suggested. Once you have the ends in and the gasket hung, you can work your way in. You can always try persuading the tubes around a bit with a pry bar wrapped in a rag to protect the coating.

Regarding the shifter linkage - if it's the backdrive rod going to the steering column from the transmission, many headers require you to remove that rod for clearance.
So that rod is basically useless then? Wasn’t really sure what it does anyway. Btw no thanks on the Pontiac headers I’ll pass 😁
 

·
Registered
Joined
·
124 Posts
Discussion Starter #15
I’ve got MAC headers on GT40P heads. Take the left side out and put a straight edge on the 3 tubes. You’ll probably find one of the tweaked. I ran into the same issue but I blame that on myself. I had one tube touching the frame rail and that to slightly flatten the side of the tube. The banging was just enough to throw the tube slightly off. I corrected the issue and the header went right in

Did your 1 tube come separate from the rest? Mines has a clamp down by the collector. I was very careful not to bend or bang them but I’ll see what it looks like I’ve tried prying up on it to get it to line up maybe that bent is some idk
 

·
Registered
Joined
·
3,526 Posts
I'm assuming the pic of the headers is showing the shorty headers which you had before with a solid flange, and the long tube headers which have the individual flanges. I have similar long tubes and I have learned over the years is to thread the bolts into the rear holes of the flanges first, and then do the front holes. I use Remflex gaskets that don't have the hooked holes, so it's a bit more difficult. On the driver's side, I start threading bolts into the rear holes on the #5 and #8 exhaust ports, and then do #6 and #7. Like mentioned previous, I thread just enough to have the bolt started and then go to the next one. Once the rears are done, then I start working on the fronts. Once they're all started in, I tighten one flange at a time.
 

·
Registered
Joined
·
19,948 Posts
Did your 1 tube come separate from the rest? Mines has a clamp down by the collector. I was very careful not to bend or bang them but I’ll see what it looks like I’ve tried prying up on it to get it to line up maybe that bent is some idk
Yes, the first tube did slip in. My advice is pull the header out and if you have a spare head available test fit it or check against a gasket. Otherwise you’ll go crazy, I know I did.

 

·
Registered
Joined
·
124 Posts
Discussion Starter #18
Ok so I spoke with Mac reguarding this situation they instructed me go drill out the hole one size bigger. He said that in some cases the powder from the coating gets too thick in areas and ends up making the holes too small. Going to give it a try and see what happens. Thanks for all that responded with good advice
 
1 - 18 of 18 Posts
Top