[scag52]

Hi , Can someone help me with this rear code. I was told it was out of a 67 chevelle. Someone told me they think it is a 68-69 chevelle. I found the one that shows the ratio ( CI1219B ) Thanks in advance.

numbers CI 1219B

NF 3917124

 

[PCB67SS]

It would appear to be a 121st day of 69 rear. Have you checking the webbing for a foundry date?

 

[VinceS427bb]

CI 1219B = 3.73~positraction / 121-day of 69-year / made in B=buffalo
NF 3917124 = early 12-bolt casting date rear for 69

 

[scag52]

Thanks for the quick replys. I was told it came out of a 67 chevelle. Heres my problem. I have it on ebay now and have it listed as a 67 rear . Will it work in a 67 chevelle or is it limited to a 69 ?

 

[Jim_66SS]

With that casting # 3917124NF it is a 68 or early 69 rear. The assembly date of CI 1219B idicates that finaly assembly was on Dec 19th(1219) at the Buffalo plant (B). The previx CI indicates that it came from. the factory as 3:73 Posi. The 68-9 rears are 1 inch wider than the 67; but the 68-9 will bolt into the 64-67. There is a little difference in the pinion angle as the ears are not located in exactly the same place on the carrier housing. One easy way to tell the wider rears (68-72) from the narrower rears (65-67) is to check the distance between the backing plate and the ouside of the lower control arm bracket, if a cigarette pack just fits in the space it's a narrow rear, if there is about 1/2" wider than the cigarette pack it's the wider rear.

The carrier housing should also have a date code cast into the housing. Something like B 12 7 for Feb 12, 1967 etc.

 

[scag52]

Thanks so much for the help. I'm amazed at how much info you guys on here have . Saves a lot of time & trouble for us rookies. LOL !

 

[DaleM]

The 3917124 was used in late 67 as well as 1968 and early 1969. The ID code "CI" was used in all three years for a 3.73 Postraction so that's not much help. As suggested, look for a date casting in one of the webs like this:

You'll have a letter for the month (A...L for Jan...Dec) followed by a 1-or 2-digit day of the month followed by a 1-digit letter for the year. This example is June (F) 21, 1967.

 

[PCB67SS]

Hopefully Dale will come back and possibly shed some light on the date stamps in the axle tubes. I originally thought it was a month / day / year thing....example the above mentioned CI 1219 B. But I did a little web search and found a reference on www.chevellestuff.com and seen it referenced as a 121 day of a year or as a julian date. Did this change for a certain model year as I believe in 67 they used the first mentioned example?

 

[DaleM]

For rear ends, engine blocks, heads, etc. it's been letter/day/month for casting numbers and stamped IDs for blocks and rear ends it's been 2-digit month, 2-digit day since at least 64 I believe.

Some don't include the letter "I" and some do. There may be more parts, but the only thing that comes to mind off-hand with julian-type dates are on TH400's.

 

[PCB67SS]

Thanks Dale I went back and re checked the web site. I was looking at the 71-72 rear axle tube examples and not 69 when they used a julian date type example?

 

[DaleM]

You're right, 71 & 72 rear axle housings were coded with julian dates. :thumbsup:

 

[Jim_66SS]

I also had some information indicating this rear was used in late 67; but was not sure, so didn't mention it. Wondering if it is true or not that the ears for the upper control arm bushings are not located in the same position on the narrow rears as apposed to the wider rears? Have heard there is a 3/8" difference in how far forward the ears are located; thus changing the pinion angle if you put a 68 rear in a 67.

 

[PCB67SS]

James I to have read that before but have never compared. I believe that is why the say you will need to use the upper control arms to match the date of the rear.

 

[Jim_66SS]

Have heard both that and the reason you have to use 67 upper control arms vs 68 upper control was due to differnces in frame and body between the years 67 & 68.