Spec Case 9" Rear End 2 Versions for the 1967 GT500

[Kent]

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...

[J_Speegle]

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

[TLea]

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%

[Kent]

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.

[J_Speegle]

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

[430dragpack]

#591 has both plugs, known original.  Scheduled Ford build 12-22-66,  Built 1-11-67.

[Kent]

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.

[Scode67FB]

Are there any known examples of SPEC cases or any other Nodular cases without a fill plug? I've never seen one.

[Kent]

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.

[430dragpack]

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.

[Kent]

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.

[430dragpack]

Kent,
What is the first car they were installed in?

[Kent]

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

[68stangcjfb]

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.

[TLea]

135 cars i've seen have dated nodular cases, We also see spec cases on some early 68 350 4 spd cars