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SAAC HQ => Concours Talk => Topic started by: Kent on October 17, 2022, 03:25:23 PM

Title: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Kent on October 17, 2022, 03:25:23 PM
I would be interested to bring together at which timeframe the Spec Case became the drain plug from observations, pictures, knowledge etc.

I know that the first GT500´s came with 9" housings with a drain plug in the axle and the spec case was without
from what I saw the may/June cars sometimes came sometimes with both drain plugs so for the rear end housing and spec case
and then the last ones had 9" rear end housings without plug and the spec case had a plug.

Is that correct so far. Maybe we can bring it together here to keep this for the files. Thanks...
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: J_Speegle on October 17, 2022, 03:47:16 PM
Will be difficult to confirm which are original and which have been replaced or swapped over the years given the lack of casting or stamped dates on both. Have found the third members to be easier to group than the rearend housings.

Plenty of reasons for each to have or have need to be replaced over the years.


Can share I do have a fair number of housings with fill plugs in them later than we originally believed or thought. Also as you mentions there are plenty fo examples of cars currently or in the past with fill plugs in both.

Good luck with the effort
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: TLea on October 17, 2022, 04:20:39 PM
I've recorded April 22 Ford build SPEC case w/fill and housing w/fill plug. Can't say 100% as not original owner but knowing the car's history I'd give it 99.9%
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Kent on October 17, 2022, 04:28:17 PM
I think it had to do with the swap from no plug in the rear end housing to plug in the spec case when these mix in some cars came up with both. So maybe the spec case with the plug came earlier than the rear end with no plug.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: J_Speegle on October 17, 2022, 04:34:44 PM
Quote from: Kent on October 17, 2022, 04:28:17 PM
I think it had to do with the swap from no plug in the rear end housing to plug in the spec case when these mix in some cars came up with both. So maybe the spec case with the plug came earlier than the rear end with no plug.

Yes there was not attempt to coordinate the two changes other than to make sure at least one had a fill plug



An additional thought about the housing research. You should seek out and include Mustangs built at San Jose with 9" rearends since there was no different for workers for that item between Shelby and Mustangs and it will increase the pool of information a fair amount.  Do currently, on record, have just less than a dozen examples of those with fill plugs on cars assembled/finished in the month of June 1967

Also if you want to go deeper for the third members a shadow survey of 9" third members from none and early 3rd members from other Fords would help add allot more information as to when the change at the producer of the third members switched from the no-fill plug to the fill plug version.


I've been doing both for a number of years but have not updated or focused on these two specific patterns lately.  Hundreds of similar ongoing surveys. Some published on CMF
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: 430dragpack on October 17, 2022, 07:52:21 PM
#591 has both plugs, known original.  Scheduled Ford build 12-22-66,  Built 1-11-67.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Kent on October 18, 2022, 03:28:42 AM
ok that's earlier than I thought, so its really possible that there are more GT500 with both plugs then with just one. Maybe some of the engineers at Ford thought why do we have 2 plugs and then they got rid off the plug in the housing for a cleaner look and cost saving.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Scode67FB on October 18, 2022, 12:08:21 PM
Are there any known examples of SPEC cases or any other Nodular cases without a fill plug? I've never seen one.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Kent on October 18, 2022, 02:19:48 PM
Yes the space cases without plug are out there usually found on very early cars like 67 shelby gt500, 67 Fairlane w and r and the 67 mercury cougar r and w.

On an N Case I only have seen them with plug.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: 430dragpack on October 18, 2022, 02:26:10 PM
Quote from: Kent on October 18, 2022, 02:19:48 PM
Yes the space cases without plug are out there usually found on very early cars like 67 shelby gt500, 67 Fairlane w and r and the 67 mercury cougar r and w.

On an N Case I only have seen them with plug.

....and '66 427 Fairlanes.  Although most probably have been messed with/changed, can't say I've seen a non-fill plug SPEC case in one, usually both plugs.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Kent on October 18, 2022, 02:37:38 PM
yes 66 fairlanes also, I missed that, I think it looks like they changed from no plug to plug in a spec case very early.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: 430dragpack on October 18, 2022, 02:42:51 PM
Kent,
What is the first car they were installed in?
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Kent on October 19, 2022, 04:31:01 AM
the first car with spec case was the 66 Fairlane 427 and then in 67 the Fairlane and Mercury Cougar with R and W Code and the Shelby GT500 67
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: 68stangcjfb on October 19, 2022, 06:01:34 AM
I assume you mean 68 Cougar with R & W code. I can see the early W code cars getting them, but R production started in February 68. Maybe some Mustang 135 cars got SPEC cases? They were built late December 67. About a week or so after the 7L20 and 7L21 no N nodular cases started getting made. Just for reference, my May 11, 1968 Torino GT R code fastback has its original 7M21 case with 31 spline 3.91 trac lock.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: TLea on October 19, 2022, 07:16:23 PM
135 cars i've seen have dated nodular cases, We also see spec cases on some early 68 350 4 spd cars
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: Scode67FB on October 20, 2022, 12:47:08 AM
Quote from: 68stangcjfb on October 19, 2022, 06:01:34 AM
I assume you mean 68 Cougar with R & W code. I can see the early W code cars getting them, but R production started in February 68. Maybe some Mustang 135 cars got SPEC cases? They were built late December 67. About a week or so after the 7L20 and 7L21 no N nodular cases started getting made. Just for reference, my May 11, 1968 Torino GT R code fastback has its original 7M21 case with 31 spline 3.91 trac lock.

I don't know when the non-SPEC Nodular started casting, but I have one dated "7F2."
Does anyone have a pic of a one of these Nodular with no fill plug? Otherwise, I have a hard time believing they exist. The timeframe for their use would be so short and the applications so limited that I don't think Ford would've bothered.
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: TLea on October 20, 2022, 07:19:53 AM
Pretty sure my 65 R code has nodular. Would have been dated prior to cars build (4-65) Has fill plug. Will get pics next time I go to my other building
Title: Re: Spec Case 9" Rear End 2 Versions for the 1967 GT500
Post by: 430dragpack on October 20, 2022, 07:46:30 AM
'63-64, Since they are C4AW cases, no "N", SPEC and with "N" until the DOOE bearing size change in May of 1970. 
Tim,
Are you saying '65 R code Shelby or Galaxie?  A 65 Rcode Galaxie does have a no N nodular with both fill plugs(or at least this one does), just looked at an original one couple weeks back, one owner since new. I couldn't get under it far enough to get a picture of the date code.