# How do i make headers fit my 65 gto



## pontiacyellow (Feb 21, 2013)

I tried to instal my headman headers but rag joint hits. do i need a deferent oil filter mount on passenger side. I found out it has a 1967 400 instead of the stock 389. Ideas will be appreciated.


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## Instg8ter (Sep 28, 2010)

400 is the same size block, alot of the headers have fitment problems thats why under most header discussions you will find a leaning towards the RA exhaust manifolds. Is yoru oil filter straight up and down or on a slight slant? You will want the slanted pickup and the smaller filter. Can always dent the headers in for rag joint clearance, they will tend to hit the A-arm bolts too when the motor rotates under torque on the drivers side. I found a nice set of three pipe jet coated hooker headers that fit nicely with no issues other than the gyrations it takes to get them bolted up.


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## geeteeohguy (Feb 2, 2008)

You need to take a ball peen hammer and put a small dimple at the corner of the tube where it wants to hit the rag joint stud. I did this to the Hedmann's on my '65 30 years ago, and they're still on the car, as ugly as ever. I also had to flatten out the down tubes where the Z-bar lower arm and clutch rod are, for clearance. If your car is an automatic, it will be much easier. Also, the higher you jack the car up, the easier the install, because you can tilt the header in any direction to get it in. Some guys go with taller engine mounts. I don't, because it throws off drivetrain alignment and I don't like the driveshaft hitting my floor pan. Get ALL the bolts "started" before you tighten any of them all the way. Also, sometimes it is necessary to hacksaw the flange connection points so that the flange will bolt flat to the head without twisting.


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## rickm (Feb 8, 2012)

everyone seems to have their own opinion on headers. ive installed my share and have found you pay for what you get. quality headers will always fit better because they are made to fit specific applications. they also come with detailed instructions regarding what oil filter and pick up to use, clutch component interference, motor mounts, ect. the last thing i would want to do to a new set of headers is start putting a hammer to them or hacking them up. obviosly, the best time to install a set is when your dropping in your motor. in my opinion doug's are the best quality and fit for a '65 gto. they just cost alot , but well worth the price.


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## leeklm (Mar 11, 2012)

... and remember you only lose 10hp on the dyno when using RA manifolds compared to headers and far fewer headaches. With that said, I have only ever owned cheap headers, and they suck.


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## the65gto (Oct 9, 2008)

pontiacyellow said:


> I tried to instal my headman headers but rag joint hits. do i need a deferent oil filter mount on passenger side. I found out it has a 1967 400 instead of the stock 389. Ideas will be appreciated.


The interference I had on my rag joint was with one of the nuts that hold it together. Even thought I could turn the wheel, it would just kiss the header, so I carefully marked it and removed the nut bolt, ground them on an angle and reinstalled. It misses now about 1/8" inch. 10Yrs still good! As far as the oil filter, the only way it will go into place is slide it between the header sideways and then I can rotate and align it with the filter mount, changing oil is a mess.


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## leeklm (Mar 11, 2012)

They do sell a "mini" oil filter for pontiac v8, which is what i used with headers on my 400. worked much better than a full size filter.


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## rickm (Feb 8, 2012)

the small filter is a ac # PF-61. its a late trans-am filter. works great with headers. it does change your oil capacity to 5-1/2 instead of 6.


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## geeteeohguy (Feb 2, 2008)

With a '66 I had, I ended up using a remote oil filter mount and a full size filter. Also a PITA. But I prefer a full size filter to a mini-filter.


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## rickm (Feb 8, 2012)

i also would prefer the stock oil filter for my motor. but i treat my gto better than i treat myself. the oil never gets a chance to get nasty before i do a change.


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