VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Block Core Plug

We need to replace the front core plug on ”˜51 216 block. Based on the Master Parts List and some other searches I think we want a 2” Welch or dome plug. The part number is 3835121.

Am I reading things correctly?

The hole in the front of the block does have a shoulder or lip that the plug will seat against. We do plan to use some type of sealant. Plus we will clean that hole so the plug can seat properly.

I believe itis not a cyp type because in the 1959 parts book any of the plugs that are cup type are described as such and the 2" has no description.

Hi Gene,

Hope you are staying cool during this hot spell.

Thanks for sharing your thoughts. That is how I am interpreting the parts listing.

I also have searched using the Chevy part number. It cross references to Dorman part 550-028 which is a 2” dome plug.

giving this more thought and going back in to my memory the plug is a special part that is why it has a Chevrolet part number rather than just a general hardware number like the other plugs.
It i was a fairly flat plug with just a sall lip aroud the edge

Hi Gene,

Thanks for that additional detail. Based on the pictures both the Dorman part and the Sealed Power (Federal Mogul) plugs have that small lip.

That might explain why we are having trouble finding one on the shelf locally. It is not just a regular 2” domed plug.

Correct

Today we installed a regular 2” domed plug in the front of the block. We did use some sealant and put a nice dimple in it to seat it. It was a nice snug fit into the counterbore.

Even though the picture of the Sealed Power plug showed a small lip the part we received did not have that.

The counterbore is deep enough that a domed plug with a small lip would fit nicely. The outside edge of the domed plug we installed is below the surface of the block.