Topic: 1966 K-Code w/ C-4 Automatic?

[Pete Bush]

I'm beginning my research on the front spring codes for my Build Sheet blog, and I have, what I believe to be contradictory information. K-codes had a spring designation (according to the 65-72 Master Parts Catalog) for automatics on cars without thermactors before 2/14/66.  However, cars with a thermactor did not, nor did cars after 2/14/66. I was under the assumption that an automatic was available on HiPo cars, but it was a heavier duty C-4 than was available on T, C, and A codes. Saw the same thing when I was researching driveshafts.
Can someone explain?

[5F09CNot4Sale]

To handle the K code they did indeed put in a modified C4. I would suggest going over to the Hipo site and doing a search over there. There is tons of info on this very subject over there.

http://www.hipomustang.com/hpmx/default.asp

Here is an example of what is over there
http://www.hipomustang.com/hpmx/topic.asp?TOPIC_ID=9873&SearchTerms=c4

[Pete Bush]

Thanks!

I'll poke around some and see what I can find.

[J_Speegle]

Kind of got lost in your wording but would offer.

First - stop using a document designed for selecting replacement parts of a vehicle that was already 6-8 years old.

Of course there is conflicting information in that Parts Catalog - you just found one of many

The lack of a spring number may just indicate that by 72 there were no longer servicing those particular springs or they had combined them with others to reduce the number they needed to carry

The K code C4 was available behind the K code in 66 - governor, valve body and a couple of other changes if I remember correctly

Also K codes were not equipped (some based on where the car was to be delivered) with thermactors until April 67 so you only had a few months of production - very few were built

[Pete Bush]

Jeff,

In order to begin a build sheet decoding process, I've had to start with an understanding of what components (and part numbers) were utilized under what circumstances. A 1966 6-cylinder driveshaft, for instance, could have been one of three different parts - depending upon which transmission it bridged to the rear end. So far, I've found two different codes, one for the 3-speed and one for the C-4 driveshafts. I suspect I'll find a third code when I stumble across a Dagenham build sheet. Regardless of the paint markings found from a particular plant, which seems to be a very contentious subject, the part would still have to be the correct service rating (length and diameter of a driveshaft/transmission combination, or weight service rating for the front springs of a K-code with a C-4 and thermactor). The 1965-72 Parts Manual has been a great aid in determining these different parts. As you note (and I've found out) the Parts Manual is not a complete compilation.

And then there's the "real world" differences, where I'm sure I'll find instances where a build sheet might call for the code of, for instance, a 3-speed manual transmission, and  a Falcon or Fairlane part was utilized. When I get to that build sheet I'd be curious to see whether the transmission code changes as well.

If there is a more accurate (complete) reference I can used instead of the parts manual, perhaps you can direct me to it?

[CharlesTurner]

The single-year master parts catalogs are also a great resource as some of the numbers are dropped or superseded in later versions of the MPC.  The '66 version is tough to find.

[J_Speegle]

Agree with Charles that one of the best sources are the Parts Catalogs printed right after your year of interest was built.  Even better would be a complete set of assembly manuals with all of the change sheets.

I would add that a complete set of TSB articles from the period your interested in can also give you allot of info about what they were doing and changing on the line

[Road Reptile]

 Hi all,
 Just a few comments from the Ford side of things,it is important to keep things in proper order,and as Jeff has mentioned service parts are often superceeded and eliminated as time passes.Even the MPC gets an update and should normally reflect this change..it can be for several reasons and most you would not guess.
The C-4 was first offered in a Mustang with a K engine in 66,and is designed to allow more driving options for shifting up or down .A Dagenham 4 speed was not up to the torque output and was not a popular gearbox,left quite early in the program.Springs are a science and they are VERY weight specific which explains why so many different ones are listed.Remember the Mustang was the car designed to be designed by you.

Enjoy R.R.

[Pete Bush]

A Dagenham 4 speed was not up to the torque output and was not a popular gearbox,left quite early in the program.

R.R.
That seems to be true in Dearborn. But Jim Smart's Mustang Production Guide has 6-cylinder's with 4-speeds as late as June 1966 in San Jose, and July 20th in Metuchen. I was under the impression that the only 4-speed available with the 6-cylinder was the Dagenham.

Springs are a science and they are VERY weight specific which explains why so many different ones are listed.

My current research on front springs is proof of this statement. There seem to be many, many different possible applications and multiple codes!!! This is one of my most difficult codes to break.