Topic: 66 Running Changes Main Thread - San Jose Findings

[J_Speegle]

Posted the other day a graphic I was thinking about incorporating in surveys and results of running changes on the site to graphically represent know or confirmed ranges of the two or more versions as well as the "gray area" at the time of the study. It was suggested that we give it a try with a pilot. To that end figured we would start with an easy even year thread since the second year of a body style normally has less of these changes. So post what you understand was affected by running changes and I'll keep an ongoing list here in the first post. From there we'll collect data, assemble the first report and see how it works.

To keep the thread from getting too long or out of hand please don't post that you found this version or that on car 6F07C2345xx (for example). We can save that for the research period and for the individual change threads. Just trying to identify the features during this first effort. Will break out the findings by plant of course.  Hope we can work through other plants also

Drivetrain

Engine

E1- V8 motor mount style - Currently have the change possibly taking place in the 130xxx-140000 range MPC list the change being made on Nov 1 1965
       https://www.concoursmustang.com/forum/index.php?topic=25068.new#new

E2- Hipo/K Code Alternator pulley and fan change -

E3- V8 Head design change -

E4- V8 Intake end gasket change -

E5- V8 Valve spring change (Engine #10 Change) -

E6- V8 Piston change. -

E7- V8 Valve cover change - BM reference

E8- Thermactor gulp valve change -

E9- 6 Cyl Thermactor pump silencer change - Feb 14, 1966 Shown in reply #8 in the thread linked below
       http://www.concoursmustang.com/forum/index.php?topic=14325.msg89264#msg89264

E10- Ignition coil marking - FoMoCo to AUTOLITE- Marking changed at the plant that supplied the coils somewhere between March and May 1966
       https://www.concoursmustang.com/forum/index.php?topic=2947.new#new

E11-

Transmission

TR1- Manual transmission clutch changes - numerous related changes (Reference 2/14/66)

TR2- 3 and 4 Speed lower shifter boot - Add to production approximately Feb. 16, 1966 according to a TSB #844
         http://www.concoursmustang.com/forum/index.php?topic=18346.new#new

TR3-

TR4-

TR5-


Rearend

R1-  9"/K-code differential housing from round to hump -

R2-

R3-


Engine Compartment

EC1- Inner fender panel/battery box positive cable shield (stapled - plastic rivets) Change took place during Feb 1966.
         http://www.concoursmustang.com/forum/index.php?topic=14988.msg93435#msg93435

EC2- Radiator identification markings - Stamped in top tank or sodered on metal label. Change took place at Western Modine (the provider) July 1965
         http://www.concoursmustang.com/forum/index.php?topic=19068.new#new

EC3- Horn style. (10/4/65 reference)  Horn bracket change from the dimple/button to the finger/tab style. Appears to have taken place during late Nov to at least mid Dec 1965.
         http://www.concoursmustang.com/forum/index.php?PHPSESSID=d97t31057mg9p0k4qqi3pfbs87;topic=19184.new#new

EC4- Horn wire (blacked out or not) -

EC5- Transition from unpainted to painted engine compartment rear splash shield upper screw visible in engine compartment. Survey indicates mid March 66 change.
         http://www.concoursmustang.com/forum/index.php?topic=19117.new#new

EC6- Starter Solenoid -  Currently between late May 66 - early July 66.
         http://www.concoursmustang.com/forum/index.php?topic=16575.new#new

EC7- Wire harness changes. Other than the model year change at the beginning of production. -
 
EC8- Windshield washer bag change - White to gold printing and possibly bracket change -

EC9- Disc brake master cylinder change - Change of brake line attachment and dating styles
         http://www.concoursmustang.com/forum/index.php?topic=17340.msg109190#msg109190

EC10- Radiator hose clamps - Change from band to wire style
       http://www.concoursmustang.com/forum/index.php?topic=23808.0

EC11- Upper clutch release lever spring addition/change - Spring, attachment bracket, Z bar. MPC suggests that the change took place Feb 14th  Survey shows that the change took place likely during Feb-Mar 1966. Documented between (at time of survey 6R1639xx - 6R1789xx. Earliest cars with hole did not use a rubber plug to cover the unused hole on automatic transmission cars.
       http://www.concoursmustang.com/forum/index.php?topic=23645.msg147375#msg147375

EC12- Radiator shroud change - From rubber pad on passenger side retained with four heavy duty staples to no staples or pad
       https://www.concoursmustang.com/forum/index.php?topic=4614.0

EC13-

EC14-

EC15-


Exterior

EX1- Hood frame design changes -

EX2- Drivers side fender lip reliefs  (raised triangles). Took place (fender stamping date) from Jan 14-18th 1966 according to findings.
         http://www.concoursmustang.com/forum/index.php?topic=1399.msg119005#msg119005

EX3- Rear valance screws - Since these were installed at two different points in the assembly line we found two different styles typically used on each car.
       https://www.concoursmustang.com/forum/index.php?topic=29520.new#new

EX4- Fastback trunk lid inner panel change - Rectangle to round cut outs - Appears change took place with job #1 at San Jose. Related discussion with pictures of both 65 and 66 versions
         http://www.concoursmustang.com/forum/index.php?topic=17928.msg113386#msg113386

EX5- GT Fender emblem change - Ceramic to plastic
         http://www.concoursmustang.com/forum/index.php?topic=20665.0

EX6-

EX7-


Interior

I1- Tire pressure decal location. Change took place in late Nov 1965
         http://www.concoursmustang.com/forum/index.php?topic=14792.msg92262#msg92262

I2- Pony/Deluxe door panel changes -

I3- 4 way flasher wire loom - Separate or integrated with dash loom -

I4-


Trunk

T1- Passenger side wheel house depression. Appears to be a feature added after a point in production for clearance purposes. Change over period has been identified at the end of March to the beginning of April 1966. Sorry can't be more specific due to the lack of exact completion dates for the cars.
       https://www.concoursmustang.com/forum/index.php?topic=26253.new#new
 

T2- Fastback passenger side trap door surround panel - Use and application of the flat and dimpled panel. 
       https://www.concoursmustang.com/forum/index.php?topic=29487.new#new

T3-


Undercarriage

U1- Rear V8 brake cylinders from 29/32" to 7/8" -

U2- Rear backing plate knock-outs for brake shoe adjustment - Started during the last few months of 65 production so not a 66 change
         http://www.concoursmustang.com/forum/index.php?topic=15041.msg93741#msg93741

U3-

U4-


Last Updated - 3/25/24

[midlife]

How about the change over to the integral emergency flasher wiring?  I think that took place in March 1966.

Yes, the underdash and tail-light harnesses, along with integrating the backup lamp harness, was also included in this update.

[J_Speegle]

NOTE: Item numbers have changed over time as items were reorganized, corrected, altered and added to

No 2 - This was asked on the Shelby forum (I think) and it was determined to be shift/worker related.

Don't recall that thread. As a response to a recent question I discovered that it appears that it's running change rather than a specific individual. At least so far.

No 4 - What variations are there, aka what do we look for?

There appears to be two changes. They might be related or not. The TSB refers to a change from unsealed to sealed horns being introduced on the date listed. In addition the use of 65 style (where they bolt to the radiator support) to the 66 style. The second will be easier to document through pictures and original cars

No 5 - Horn wire where?

"blacked out or hidden behind the grill. From radiator support to horn like done for a period at some plants in 65. This may not hold up to research but it can be removed if it does fail

No 8 - That's in the MPC as Nov 1, 65. That would be the time frame in question. (A June car would not be included.)

Unfortunately with 65-66s we will not have real dates for the cars so they Nov date will likely be the change over date. Will at least go through the process to also use (as best we can) cars to confirm. Just basic research mythology

No 12 thru 17 - What are the differences to look for?

[/quote]

All related to internal engine changes (pistons, heads, valve train....). Going to be tough to document but these were in response to your comment about working in TSB articles and changes documented there into the time lines.

[J_Speegle]

So how would you like the responses? The estimated build date from the door tag and whether or not the car had the 1 through 17 features? so for instance, for #2:  #2. 1/12/66 on left side of glove box door.  Is that how you would like them?

Think this is the plan

- Will open threads in this section. Something like 66 Running Change Survey Thread - Tire Pressure Decal Location

- Participants would provide the cars VIN (includes a ton of info in a short amount of space) and the projected build date

- If the change could include a specific accessory (for example AC) that will also be included in the request so that we limit/focus response and eliminate the 6 cylinder responses to V8 related questions for example

Sound good? Well give it a try and see how it works out.