63_intake manifold (3844461) stud replacement puzzle

[Steve D.]

I was replacing the intake studs to accommodate a spacer when I discovered that one of the stud holes was 4" deep. I removed the existing studs and ran a brush in to clean the threads. Three of the holes (the 2 front and passenger rear) are about 3/4" deep, but the 4th (driver rear) is 4" deep (measured). The manifold PN is 3844461. Is this usual or unusual?

[Chris D.]

Re: 63_intake manifold (3844461) stud replacement puzzle

Steve,

3844461 is a 64 manifold, isn't it, with the brake booster boss threaded ?
The casting and basic design of this manifold goes back to 62 when that stud hole was used as a vacuum source through a hollow stud. I have a 63 3794129 that has the same vestigial deep hole.

[Steve D.]

Re: 63_intake manifold (3844461) stud replacement puzzle

Chris

Yes, there is a boss with plug in the manifold behind the carburetor. Are you saying that the carburetor stud hole connects to an area that can be used for a vacuum source? If so, it seems that vacuum leaks at the stud would not be uncommon.

[Joe L.]

Re: 63_intake manifold (3844461) stud replacement puzzle

Chris

Yes, there is a boss with plug in the manifold behind the carburetor. Are you saying that the carburetor stud hole connects to an area that can be used for a vacuum source? If so, it seems that vacuum leaks at the stud would not be uncommon.

Steve-------


Yes, that's how it is. That's why it's a good idea to use sealer on this stud. However, I don't know if the factory ever did.

[Steve D.]

Re: 63_intake manifold (3844461) stud replacement puzzle

Joe

Is this unique to the 461 manifold, or are there others with similar design?

Edit: After re-reading Chris's post, I realize the design was used from at least 62 to 64. Did it survive after that?

[Joe L.]

Re: 63_intake manifold (3844461) stud replacement puzzle

Joe

Is this unique to the 461 manifold, or are there others with similar design?

Edit: After re-reading Chris's post, I realize the design was used from at least 62 to 64. Did it survive after that?

Steve------


I believe all of the 1958-62 carbureted Corvette manifolds had the feature. It was not used after 1962 but I do not know if any of the manifolds after 1962 were drilled through for the one stud.