# headers and manual tranny linkage



## ylwgto (Oct 27, 2009)

I'm starting to think about putting together parts to do a manual conversion this summer. 

If I go the route of a 4-speed, I'm wondering if headers generally interfere with the z-bar linkage and if so is my only option a hydraulic thow out bearing set up?

eyeballing one if these kits rather than tracking all the stuff down:








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## PontiacJim (Dec 29, 2012)

ylwgto said:


> I'm starting to think about putting together parts to do a manual conversion this summer.
> 
> If I go the route of a 4-speed, I'm wondering if headers generally interfere with the z-bar linkage and if so is my only option a hydraulic thow out bearing set up?
> 
> ...


I don't think you have quite the issue with the z-bar on the 1967 and earlier cars as you do with the 1968 and swivel type z-bars which are bulkier. Kit appears to be complete less your pedal pads. Brand of headers can also make a difference.


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## nhcd538 (12 d ago)

Is this really an issue? How many manual transmission GTO's of all years used headers? Makes sense that maybe a certain brand of header might have interfered with the Z-bar linkage...but just based on sheer numbers it had to be a very rare problem.

I'm swapping a 4-speed into my 67 in place of a TH400 and I have headers. If the headers derail my plans I'll go back to stock manifolds before I'd do hydraulic TOB or keep the slushbox.


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## geeteeohguy (Feb 2, 2008)

I have had issues with Z-bar clearance on every '65-'66-'67 GTO I've put headers on. I've had to flatten the down tube, and on my old '66, I had to weld a flag onto the top arm of the Z-bar in order to clock it forward enough for the lower arm with the push rod to clear the down tube of the header. Worked out fine. I've never had a set of tubing headers of any brand that simply 'bolted on' without the need of some blacksmithing.


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## Baaad65 (Aug 29, 2019)

ylwgto said:


> I'm starting to think about putting together parts to do a manual conversion this summer.
> 
> If I go the route of a 4-speed, I'm wondering if headers generally interfere with the z-bar linkage and if so is my only option a hydraulic thow out bearing set up?
> 
> ...


From everything I've read here and having a '67 4spd with headers back in the day I'd say ditch the headers, they're only good for a few more ponies at what 6000 rpms? But they are good at hair loss, creating alcoholism, and ending up in a straight jacket...but it's your car...let us know how the jacket feels I've never been in one, yet


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## PontiacJim (Dec 29, 2012)

nhcd538 said:


> Is this really an issue? How many manual transmission GTO's of all years used headers? Makes sense that maybe a certain brand of header might have interfered with the Z-bar linkage...but just based on sheer numbers it had to be a very rare problem.
> 
> I'm swapping a 4-speed into my 67 in place of a TH400 and I have headers. If the headers derail my plans I'll go back to stock manifolds before I'd do hydraulic TOB or keep the slushbox.


Many seem to have one issue or another with headers and manual transmissions and a few seem to get lucky. You have to remember that "back in the day" there were more header builders & brands available and like all things, you got what you paid for. Tube diameter size may also play a role.

I went with the Doug's headers which are said to fit well, but since I have a '68 with the "swivel" Z-bar, the instructions do say to use the earlier 1965-67 straight tube style Z-bar which I got. Have not installed them, so I will know how well the fit really is. I can also do whatever fabricating on the Z-bar if needed. They certainly were not the inexpensive old school "Black Jack" headers I had purchased for a small block Chevy I owned.


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## ponchonlefty (8 mo ago)

Baaad65 said:


> From everything I've read here and having a '67 4spd with headers back in the day I'd say ditch the headers, they're only good for a few more ponies at what 6000 rpms? But they are good at hair loss, creating alcoholism, and ending up in a straight jacket...but it's your car...let us know how the jacket feels I've never been in one, yet


mine fits pretty good. jacket that is. headers used in the right environment are great. they can increase torque and hp. on the right combo.


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## Baaad65 (Aug 29, 2019)

ponchonlefty said:


> mine fits pretty good. jacket that is. headers used in the right environment are great. they can increase torque and hp. on the right combo.


Well I didn't even consider it after my '67 pita, I ended up switching those out too for regular ram air manifolds because the larger aftermarket ones weren't available back in '85. If you look up a comparison the large ram air manifolds like I have flow as good as headers until a pretty high rpm or a very high flowing head and then it only really matters if you're bracket racing. I have an X pipe that increases tourqe plus I can't get the torque I have to stick the 9.5 drag radials...well I did once 😉


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## ponchonlefty (8 mo ago)

Baaad65 said:


> Well I didn't even consider it after my '67 pita, I ended up switching those out too for regular ram air manifolds because the larger aftermarket ones weren't available back in '85. If you look up a comparison the large ram air manifolds like I have flow as good as headers until a pretty high rpm or a very high flowing head and then it only really matters if you're bracket racing. I have an X pipe that increases tourqe plus I can't get the torque I have to stick the 9.5 drag radials...well I did once 😉
> View attachment 160787
> View attachment 160788
> View attachment 160789


yeah,that torque is why i chose to stay with the 400 it hits the tires less and gets you moving. in my situation i have a 9.3 rear so it should work together pretty well and hopefully traction wont be as much a problem.but long tube headers vs manifolds the headers win if racing. for the street manifolds are a better choice. honestly i think you could have went with a 400 and go faster on the street.and not blow the rear end.spinning ain't winning as it is said. i am interested in how your build turns out.its all fun no matter how we get there.


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## Baaad65 (Aug 29, 2019)

ponchonlefty said:


> yeah,that torque is why i chose to stay with the 400 it hits the tires less and gets you moving. in my situation i have a 9.3 rear so it should work together pretty well and hopefully traction wont be as much a problem.but long tube headers vs manifolds the headers win if racing. for the street manifolds are a better choice. honestly i think you could have went with a 400 and go faster on the street.and not blow the rear end.spinning ain't winning as it is said. i am interested in how your build turns out.its all fun no matter how we get there.


I love the 461, smaller journals that get oiled better, then the longer stroke that doesn't spin so fast it's right at 500hp/530lbs tourqe, you just have to have the right suspension set up to get it to the ground, when I raced I spun a little because the tires crept up to 28lbs then I lowered them to 15 and the track got sprayed down with stickem, it must of bit because I tore up a 12-bolt. The Dana S60 has raised upper arm connections so like installing hop stop bars then I have Spohn adjustable upper arms with roto joints going on and Hotchkis single adjustable shocks I set loose so the front comes up and the rear squats, and the SSM lift bars change the lift angle to more of the middle of the car instead of way in front, putting more weight on the tires. I found the weak link so hopefully I do better next fall 👍


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## lust4speed (Jul 5, 2019)

Only trouble I had with the Z-bar on my '67 was the zerk fitting stock location faced directly forward and tried to occupy the same space as the down tube. Repositioning the zerk to the rear of the tube solved the problem.

One of the problems of the internet is everything gets repeated and unfortunately it quickly becomes taken as fact. The RA/HO headers are pretty nice but from dyno tests I have observed the cast iron is down in power in all RPM ranges compared to tubular headers. The discrepancy between cast iron and headers does increase with CFM, but the cast iron manifolds are giving up horsepower in all parts of the curve. Really if you think about it you are asking a short, cramped product with sharp bends to compete with long, mandrel bent easy flowing tubes.


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## Baaad65 (Aug 29, 2019)

Sorry I got off topic and rambled but that was not me it was Jack, he shouldn't be allowed to post especially late on Friday night...he should just listen 😉


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## Baaad65 (Aug 29, 2019)

lust4speed said:


> Only trouble I had with the Z-bar on my '67 was the zerk fitting stock location faced directly forward and tried to occupy the same space as the down tube. Repositioning the zerk to the rear of the tube solved the problem.
> 
> One of the problems of the internet is everything gets repeated and unfortunately it quickly becomes taken as fact. The RA/HO headers are pretty nice but from dyno tests I have observed the cast iron is down in power in all RPM ranges compared to tubular headers. The discrepancy between cast iron and headers does increase with CFM, but the cast iron manifolds are giving up horsepower in all parts of the curve. Really if you think about it you are asking a short, cramped product with sharp bends to compete with long, mandrel bent easy flowing tubes.


Yes I see that in some articles that did testing but stock motors didn't really benefit but the bigger horse power better flowing motors did but still its only around 20hp and shorty headers were worse than ram air manifolds. Still not worth wearing the straight jacket for 😉


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## ponchonlefty (8 mo ago)

Baaad65 said:


> Yes I see that in some articles that did testing but stock motors didn't really benefit but the bigger horse power better flowing motors did but still its only around 20hp and shorty headers were worse than ram air manifolds. Still not worth wearing the straight jacket for 😉


but they're in style now.sanity is overrated.


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