-73 500 cid intake manifold carb threads

[Finndorado]

Hi Guys

Does anybody happen to know or have an intake manifold at hand to check the carb attachment threads depth.
I`m afraid I cracked the rear passenger side threads when installing the QJet.
Did it with a digital Bahco torque adapter, which I don`t like after using it few times, there is just a tone not to tighten anymore,
which you can do accidently in a bad position, or relatively short wrench and using twisting power.
Your muscles wont release at the right point as a traditional torque wrench.
I had the right torque and scale (don`t remember them know, it was last autumn), but cracking apparently did happen,
it just felt so, and I didn`t tease the bolt anymore after this feeling.
Later I was told that don`t use a torque wrench (or adapters) in other than engine head assembly.
About this issue I also got a tip to use longer than standard bolt, to reach healthy threads, that`s
why I`m asking the depth.
The other/better way is to use Helicoil, right ?
Should you or should you not use a washer with those four bolts, mine had no ?
I have understood there are different kind of intake manifolds, mine is in the picture.
(there is a piece of old gasket around the particular hole, but it was completely completely removed before installing).

Thanks
Mika

[The Tassie Devil(le)]

G'day Mika,

I would be installing a helicoil in the manifold as that hole is bottomless, and opens up into the Intake Manifold passage. (Just checked a manifold I have here)

To get the depth, you will have to make up a simple "L" shaped hook out of a piece of wire, and put it into the hole, and lift it up till it touched the roof of the passage, and mark the top where the wire protrudes.

When installing a Helicoil/drilling, you will need to contain any particles that drop into the passage, as you don't want them getting any further into the engine.

Using a longer bolt that protrudes into the passage won't really cause a problem as you don't appear to be building a race engine.

Bruce.

[Finndorado]

Ok, Thanks Bruce 👍.

Mika