BB V8 Rear Main Seal ID

[LSS&B]

I received this big block V8 rear main seal retainer with narrow side seals in a box of parts years ago.
Has a PDDC logo and last 5 of casting number looks like 21389.
Is this from a later factory big block?
Or is it something MP produced after big block V8 went out of production?
Thanks for your help!

 

[69Bee]

1821389

 

[boboh1]

Here is a picture of mine from my 1969 383. I think my side seal channels were larger

 

[rickseeman]

No, it's earlier. I don't know what that notch is. I say it's not BBM.

 

[69Bee]

No, it's earlier. I don't know what that notch is. I say it's not BBM

Here is a pic of the 1961 parts manual...

As far as the notches, some one could have done that on a mill for some reason.

 

[LSS&B]

Here is a picture of mine from my 1969 383. I think my side seal channels were larger

View attachment 1911743

Agree. I have a 2128895. Side seal channels are at least double the size of the 1821389 that I posted.

Here is a pic of the 1961 parts manual...

View attachment 1911777

As far as the notches, some one could have done that on a mill for some reason.

With the milled notches at the edges of the parting surface, should my 1821389 rear main seal retainer go into the recycling bin? I don't see how it can seal, if those notches are not factory.

 

[RemCharger]

The oil pan bolt holes are open. Weird

 

[69Bee]

Agree. I have a 2128895. Side seal channels are at least double the size of the 1821389 that I posted.

With the milled notches at the edges of the parting surface, should my 1821389 rear main seal retainer go into the recycling bin? I don't see how it can seal, if those notches are not factory.

You could try to sell or use. Sealer would be needed on the sides as well as the pan bolts as they are open...

 

[RemCharger]

Here's a brand new one.

 

[LSS&B]

Here's a brand new one. View attachment 1912218

Thanks. This one is original to the engine. Looks same. I plan to clean & reuse it. 1821389 was an extra part. I doubt anyone will want it, given that we know it has been altered.

 

[RemCharger]

Was it altered? Or is it some early retainer.

 

[LSS&B]

Was it altered? Or is it some early retainer. View attachment 1912451

By the notches cut on the sides, posters above are saying the 1821389 retainer side channels were milled for some unknown reason