I am looking for some information regarding a set of exhaust manifolds I picked up. I believed them to be factory correct Big Block Olds manifolds. 389269-LH D1 BA 337 & 389268-RH D1 337


Everything I have read says these should have raised X and a W.


I would like to find out if these are a factory original part.

 

Here are some clearer photos of both manifolds.

 

The casting numbers are correct for the 1965-68 but I've never seen a set without the large letter cast into it. Does it look like they've been ground off or just never there?

John

 

It does not appear there was ever a letter cast into them.

 

I don't know if the factory ever made these without the large letter. But since the casting code is correct they should function fine. If your doing a restoration at a level that you want everything to look correct, then you might want to sell these and get a set with the letters on them.

John

 

I sand blasted these today and they don't have any obvious signs that letters were ground off. They are simply missing. I will decide what to do with them after I get more info. I will post some pictures after the sun comes up and hope someone sees them than can positively identify their origins

 

Cleaned up nicely. Clearly no letters.

 

I just tweaked the title of your thread. Hopefully someone who knows for sure will respond.

John

 

These are 400 manifolds off of a A body.
Can you see the difference in the second line of the #s also the shape of the manifolds are slightly different.


DSC07344_zpscpujr6tl.jpg


IMG_4830_zpskfqkaroz.jpg

 

I received this message from Kurt today.








-----Original Message-----
From: Kurt
Sent: Monday, May 25, 2015 6:11 PM
To: Greg
Subject: Re: 1965-1967 Exhaust Manifolds





I'm sure you just have early ones before they cast the large letters.


'65 was the first year for them, of course.


The date code are ordinal date codes, so they have the day of the year, but not the year. However, casting revision letters/numbers are often able to help nail down the year.


Under your part numbers are the revisions.


Your LH has D1 BA


The D1 is carried right through '68 My original '67 and '68 have BR. I believe your A is the first. I doubt there is anything "less" than BA out there.


Your RH is D1 with nothing after it. My '67 is D1 then AZ. Again indicating yours is earlier.


Gathering more revision detail from '66 and before will help confirm this, but I'm confident yours are OEM.


Indications are that yours were cast about the first of Dec, 1964, so I'd expect most of the '65s not to have the X and W.

 

While not original to my 67 - I will have no issue using them on my car. This site is amazing and the people are even better. I hope to have my car completed some day and I will not hesitate to use these manifolds on it.


Thanks again to everyone for your input.

 

A slight spin to this mystery... It was pointed out to me that the shape of the flanges of these manifolds is matched to that of the starfire exhaust manifolds of 1965 (my set) has rounded inside corners on both of the outer port flanges as where the standard W/X has squared corners around the exhaust ports... The starfire manifolds have the same inside corners as my set


The suggested theory is that these manifolds may have been designed to bolt to a 425 engine in an A body car before they decided to go to with the 400 engine...


I have yet to get any feedback from someone with a set without the letters...


Is it possible that these are prototype manifolds?

 

This diagram was given to me from a member on the 442bro forum w29 boards.

Im being told these are pre-production manifolds.


To clarify - the manifolds in the engine picture attached (per the caption) is a 442 version of the 425. Notice the manifolds without the lettering and the flanges.