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How can I access the intake manifold lower nut by firewall?


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I found a vacuum leak and I tightened most of the nuts starting with the carbs out front (I need to replace the sucky black rubber? mounts with the proper soft ones anyways). The nuts were not tight that's for sure.

For the life of me, I can't get some kind of a grip on these two nuts:


so far I tried:

stubby 12mm both open and non end

no ratchet wrench can fit due to clearance

ratcheting open end

standard of course

Am I pretty much stuck with thinning down the socket wall/wrench? any idea would be great.



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yeah... i just replaced my intake manifold- these were not shall we say, cooperating. i was able to get a grip on the nuts with a small wrench (all except the upper left most one, that is in between the manifold and the coolant unit) with the closed end. the 3 leftmost bottom one's i could reach with my left hand from the radiator side of the manifold, the firewall one from the right side.

i replaced all the nuts with new 12mm ones, but someone over the years had put 13mm nuts on the manifold, so maybe worth checking that they are what you think.

meanwhile and tangentially, i discovered that its much easier to get the lower left-most nut started on its threaded rod if you don't push the manifold all the way flush with the head/its gasket...

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Well, somebody was able to put them on so it must be possible to take them off. I would buy some real cheap wrenches at Harbor Freight and grind them down.

After you get the manifold off it might not be a bad idea to grind away a bit of the material that crowds the nuts.

Good luck.

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You need one of these in your toolbox,


They are called wobble extensions.

They work in two different ways, push the socket on lightly ( or to the first "click" ) and the socket will wobble about 10 degrees, push it on a little harder and the socket catches the bottom of the wobble part and locks in like a normal extension with no wobble.

I have one that is about 5 inches long that works perfect for that nut, they come in handy all the time.

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Charlie is on target with those extensions.

The key to using a socket for those nuts is a 12 point vs.

a 6 point socket.

Also keep in mind that the factory box end wrenches are a

thin wall and work well in those hard to reach locations.

2 entire drawers in one of the tool boxes are dedicated

to the factory tools (kits).

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I don't know what you socket guys are smoking-

the nuts back in there are open- end wrench only.

He's talking about the nuts BEHIND the carb hold- down bolts in front.

I do my best to get that back manifold on before I put the head back on-

in fact, I put the rear carb on too, when I can.

Grind down a cheap wrench. The PO of my race car had used 13mm

nuts, and I have no idea how he got them on. Maybe the way I got them

off- needle- nose vice grips and a lot of swearing.

I have felt your pain. It felt like... pain.


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Thank you all for your help.

Yes gents I am trying to re-tighten the 2 bottom right nuts that connect the intake mani to the head.

No socket will mount on that thing. no clearance at the top side of the nut. I confirmed they are 12mm. The one thing I haven't tried yet is the little crowfoot open end. This might be an idea. Next I am grinding down one that's for sure.

All this for the love of carbs...


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What I wanted when I did mine, and did not have it,

was one of those modified 12- point crowfoots (crowfeet?)

that look like a section of a 12- point socket with an open

spot in them.

I used to see them at Boeing surplus occasionally, but never thought

to see who made them...


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