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Drivetrain Removal

With the interior removed it was time to turn my attention to the drivetrain removal process. The Mustang was taken to Kenny at Hold On Tight Performance who began by removing the custom exhaust that had been installed by a prior owner.

Since we are restoring this to factory original, I knew the exhaust would not be reused. As such we simply cut it out of the vehicle and threw it away.

Here you can see the custom exhaust system that was on the car when purchased.

In place of the old exhaust system will be a complete concours correct reproduction exhaust system from Scott Fuller Reproductions. The system is an exact copy of the factory original system from the h-pipe to the exhaust tips. This system not only features all the concours correct components but also features the correct Ford logos, part numbers and date code. When reinstalled it will be virtually impossible to tell this reproduction from an original.

This angle shows the new concours correct exhaust from the H-pipe back.
The H-pipe is an exact copy of the factory piece, including the alignment tabs shown.
View of the exhaust system from the correct rolled tips forward.
The muffler features the Ford engineering number and date code.
Alignment tabs are also present on the intermediate/resonator pipes for muffler alignment.
Ford logo and engineering numbers are featured throughout the system.

The hood was then carefully removed and set aside. It would need to be reinstalled before the car was sent over to the body shop for paint and body work.

In preparation for removing the C6 transmission, we disconnected the driveshaft. Upon inspection we found the driveshaft tube had been replaced at some point in its earlier life. However, the original Ford 31-spline slip yoke and tube yokes were still present.

The driveshaft was then boxed up and send sent out to Dead Nuts On to be restored. The only way to properly restore a driveshaft is to break it down to its components, restore each component and then assemble it just like Ford did it.

On the original Ford 31-spline slip yoke you can see the unique machined area cut halfway down the inner shoulders.
Both sides still had their original Ford tube yokes, though it was clear the tube itself had been replaced at some point in its earlier life.

The driveshaft restoration service replaced the tube with the same electro resistance welded seamed tubing the factory installed. This way the welds, bare steel blue seamed tube and the color of the blue heat rings on the spot welded balance weights all look real because…they are real. 

Slip yoke was restored with the correct paint code applied.
Both of the tube yokes were also restored with correct paint code, and markings.
The driveshaft was high speed balanced with the correct spot welded rectangular balance weights.
Build sheet paint codes, specific to this vehicle, were added.
The tubing was replaced with new electric resistance welded (blue seamed) tubing.

Once the transmission was removed, we carefully cleaned it and inspected it for Ford engineering numbers, date codes and the all important partial VIN. This was typically stamped into the flat boss on the spine of the transmission main case just forward of the tailshaft.

Upon inspection we were able to clearly see several Ford engineering numbers, as well as several other markings which, to this point, no one has been able to explain their significance.

The Ford engineering number, C8AP, would indicate this to be a transmission originally intended for a full size Ford or truck.
Here again we see a casting number, C6AP, which would indicate this transmission was intended for a full size Ford or truck.
Even the casting number on the servo is a C6AP.
No one has been able to explain the significance of the large ‘4’ cast into the part.
Here we can clearly see a large ‘9’ cast into the side of the part. Reason unknown.

What is most interesting is the partial VIN stamped into the transmission main case. We had expected to find the partial VIN from the Mustang stamped here. Instead, what we found was a partial VIN from a different 1969 vehicle.

Partial VIN stamped into the transmission main case.

The leading 9 in the partial VIN confirms this transmission is from a 1969, but the assembly plant code of G means this transmission was supposed to go to the Ford truck plant in Chicago. In addition the consecutive unit number is slightly higher than that found on our Mustang.

This would explain why the Ford engineering numbers found on the other transmission components indicated they were intended for a full size Ford or truck.

So, it would appear this transmission may have been either pulled from the line due to parts shortages or it was inadvertently sent to the wrong assembly plant.

Given all the the evidence, I do believe this is the transmission that came with the car when it was first assembled…even if it wasn’t intended to be.

The transmission was sent out to be rebuilt. Once it returns it will be detailed including all factory paint daubs and markings before being reinstalled in the car.

The big block FE engines were truly shoehorned into these Mustangs leaving very little room on either side of the engine. When we went to remove the shock tower braces, we noticed the original shock tower caps had been removed and replaced with a Torino style unit.

Torino style shock cap with a single nut.

I was able to locate a pair of the proper big-block Mustang shock tower caps which will be installed during the reassembly process. These are original Ford pieces that have been restored and not reproductions.

After removing the cooling system, accessories and valve covers, and with some careful maneuvering, we were able to free the engine from the car.

Unlike the C6 transmission, there is no doubt this is the original engine. Here on the rear pad you can see the partial VIN, 9R187894, stamped into the block.

Again the leading 9 would indicate 1969, R is the assembly plant code for San Jose and 187894 is the consecutive unit number for this vehicle.

The Cobra LeMans valve covers, which were removed during the engine removal process, were sent out to be cleaned, striped and powder coated by Pristine Powder Coating in the original black crinkle finish.

Cobra LeMans valve covers in the correct black crinkle finish.

We took this opportunity to remove the original Ford water pump and send it out to be restored to like new condition. Notice the date code of 9D16, which translates to April 16, 1969.

Original water pump, date coded April 16, 1969, before restoration.

The water pump was completely disassembled, then the bare housing was hot tanked and sand blasted to remove paint and rust. The housing was then painted with grey primer. A new bearing, seal, hub and bypass tube was then installed. Finally the rear cover is sealed with a new gasket. Looking at the end result it’s hard to believe this is the same water pump. It will get painted Ford corporate blue with the rest of the motor during reassembly.

The newly restored water pump is ready for paint and installation.

Before sending the engine out to be be rebuilt, we removed the exhaust manifolds so they could be sent to Jet Hot Coatings to be cleaned and ceramic coated in a natural cast iron color.

To my surprise, when we removed the exhaust manifolds and decoded the engineering numbers we found these to be the same exhaust manifolds as were used on the 428 Cobra-Jet cars.

Cobra-Jet exhaust manifolds before restoration.

The advantage of having the exhaust manifolds ceramic coated is they will retain that ‘brand new’ look for many years to come. The ceramic coating will not discolor and also reduce underhood temperatures by more than 50%, resulting in less wear on components. These will be reinstalled once the rebuilt motor is completed.

Drivers side exhaust manifold.
Passenger side exhaust manifold.

Once the engine gets back from the machine shop it will be painted Ford corporate blue and the remaining assembly line markings added before it is reinstalled in the car.

Next Step: Off to Paint!