Question? Was the 67' Shelby the only Shelby that came with the SPEC center section? and was the SPEC center section only installed in the GT500?
Thanks
Quote from: FordGT on April 30, 2018, 10:11:13 PM
Question? Was the 67' Shelby the only Shelby that came with the SPEC center section? and was the SPEC center section only installed in the GT500?
Thanks
GT500 was the typical recipient of the spec case . Some other car models used the spec case as well. I think 427 Fairlane was one.
I have seen the SPEC case in some very very early 68 500's . The 67 427 Fairlane also used a case that looks just like the SPEC case but instead Of SPEC it is says 7OR
Dominic
Tom ,
The "spec" case AKA Nodular Iron Case ( C4AW-B) was only used with 31 spline axles so , yes, GT500s only in '67. We still haven't solved the mystery as to why the foundry changed from the normal date code to SPEC and then back to date code on those cases. There wasn't anything different on them , just the SPEC.
Randy
Anyone have any pictures of the spec case with it's original pinion support?
Thanks
Tom ,
Just a "normal" C5AW "Daytona" support , nothing special. They are not dated by year. Month and day only. Looking forward to seeing you and Liz in August.
Randy
Quote from: FordGT on May 01, 2018, 05:50:48 PM
Anyone have any pictures of the spec case with it's original pinion support?
Here is a close up installed. The outer "ring" of the retainer (blue arrow) is flat so you have the machined surface that is around the whole front face rather than just sections as on other styles of retainers
(http://www.concoursmustang.com/forum/gallery/10/6-020518162905.jpeg)
And another
(http://www.concoursmustang.com/forum/gallery/10/6-020518163953.jpeg)
While I'm posting and for others that may run across this thread later using the search a couple of additional pictures
(http://www.concoursmustang.com/forum/gallery/8/6-200817224034-80842258.jpeg)
And in response to the first question about different applications here are the single and double rib designed versions cast with the SPEC. Sure many will notice that both examples are the later design with the fill plug located on the 3rd member case - drivers side
(http://www.concoursmustang.com/forum/gallery/10/6-020518163626.jpeg)
(http://www.concoursmustang.com/forum/gallery/10/6-020518163725.jpeg)
Jeff ,
Thanks for the excellent pictures. To ALL viewing them , the single rib , SPEC case was NOT used on '67 Shelby OR '67 Ford high performance vehicles with 31 spline axles. It is grey iron and not nodular iron. The correct casting number on the "inside" of the nodular iron , multi rib case is C4AW 4025 B . NOTHING else is correct for '67 high performance rear axle assemblies. Unscrupulous sellers will no doubt try to pass these off as "SPEC" cases for big money. I don't want to see anyone ripped off.
Randy
Quote from: gt350hr on May 02, 2018, 05:52:37 PM
Jeff ,
Thanks for the excellent pictures. To ALL viewing them , the single rib , SPEC case was NOT used on '67 Shelby OR '67 Ford high performance vehicles with 31 spline axles. It is grey iron and not nodular iron. The correct casting number on the "inside" of the nodular iron , multi rib case is C4AW 4025 B . NOTHING else is correct for '67 high performance rear axle assemblies. Unscrupulous sellers will no doubt try to pass these off as "SPEC" cases for big money. I don't want to see anyone ripped off.
Randy
Yes reason for posting that additional picture since it could be an attractive and leading feature (the SPEC) in an EBay ad for example
The "SPEC" date casting turns up in many strange places on many different parts. That by itself IMHO does not override doing your homework and considering the whole picture and all facts related to the part
Quote from: Bob Gaines on April 30, 2018, 10:55:18 PM
Quote from: FordGT on April 30, 2018, 10:11:13 PM
Question? Was the 67' Shelby the only Shelby that came with the SPEC center section? and was the SPEC center section only installed in the GT500?
Thanks
GT500 was the typical recipient of the spec case . Some other car models used the spec case as well. I think 427 Fairlane was one.
Bob, you are correct. The 67 427 Fairlane center section is a "SPEC" and says SPEC. The 66 Fairlanes had it as well and I assume Shelby took them from the 66 31 spline race cars to put in the 67's.
A couple other thoughts/questions ----
1. Were there nodular castings made with and without the oil fill boss with same C4 AW-B marking?
2. Was there a period in transition where some of the castings with the boss (single and double rib) left undrilled for the plug when mated with a housing that had an oil filler plug? (67 time period)
Kurt
I have been building/re building 9" Ford differentials for over 50 years and never have I seen a nodular (C4AW-B or DOOW-B) case without the oil fill plug hole. Single rib cases yes. I have seen them without the fill plug hole drilled and tapped. I haven't tracked the time frame on the single rib cases. Just the nodular ones.
Randy
This case is the double ribbed case with the C4AW marking. Also has the filler on the drivers side.
Pinion support on this case is a Daytona C5AW with built date of B8. Did these SPEC cases come with a Daytona pinion support or just standard support?
Thanks
Yes , what you have is correct!
Anyone care to share concours correct paint splotch details on their GT350 carrier and steel axle housing?
Early 67 calendar year preferred (with fill plug in housing and carrier).
PM or email if you don't care to share publicly.
On EDIT: This question moved to its own thread:
http://www.saacforum.com/index.php?topic=4106.0
Could SPEC be an abbreviation for Special?
Yes it is! The question nagging me for years is why the foundry changed it's practice of using that area for the casting date. My friend Kerry Wortman has narrowed down the date of time these were cast in ( '67 only) but finding a Detroit Iron Foundry worker that can say "why" it was done has not happened. The SPEC tag has been used on cylinder heads and other parts and so far the only tangible possibility (IMHO)was these parts were cast at the small run "specials" foundry , not the huge Detroit Iron Foundry that normally did them. Again "why" hasn't been answered. I know there is a specific reason that will get a "of course , that's why" response but it remains "to be discovered". My "educated guess" could also explain why a single rib version exists.
Randy
SPEC case on my 68.5 Survivor Car.
Perhaps by 1969 Ford switched to labeling with the N . Was the N case made in the regular foundry or still in the other Special foundry?
Randy,
The DIF letters found on castings refers to the Detroit Iron Foundry. CF and WF are on parts cast at Cleveland and Windsor Canada ( respectively). "I" am PURELY guessing ( though an educated guess) that the SPEC instead of the date code was done because of a foundry change. I have NOTHING to back it up on except my knowledge of other parts that had SPEC on them. Not all of those parts with the SPEC on them were "performance" parts but some were. I have above average knowledge for a "non Ford plant worker" ( from years of study and interviews of those who did work for Ford) as to how things were done "in the day" I do NOT know it all and never will. I learn something new every day. Until I ( or anyone else) can validate my GUESS , use caution in repeating it. That is how "myths " get started.
Randy