Options A33 AND D56

[ericisback]

if a car has the A33 track pak option (with a 3.54 axle ratio) and the D56 option for a 3.55 axle ratio, which one does it get?

 

[hunt2elk]

My guess is if you had a 440 or 426 with a 4-speed, a Dana 60 was required. That would come with 3.54's. Any other motor with a 4-speed, or these 2 with an automatic would come standard equipment with the 8 3/4 rear. That would have a 3.55 ratio. Of course you could upgrade to the Dana on the auto 440 and 426 cars as well.

 

[ericisback]

My guess is if you had a 440 or 426 with a 4-speed, a Dana 60 was required. That would come with 3.54's. Any other motor with a 4-speed, or these 2 with an automatic would come standard equipment with the 8 3/4 rear. That would have a 3.55 ratio. Of course you could upgrade to the Dana on the auto 440 and 426 cars as well.

My car is a 440 4-speed. If the A33 was an added option, would it make sense to build the car with the D56 option? It doesn’t seem like you’re adding anything useful?!?

 

[hunt2elk]

Your car would have come from the factory with a 3.54 Dana rear. I don't have my white books in front of me, but would imagine that the D56 is for a car that came from the factory with a 8 3/4 rear and you checked off the box to upgrade to 3.55 ratio. You couldn't have optioned your car with D56.
3.54 in Dana's and 3.55 in 8 3/4's, just the way each were made.

 

[ericisback]

My invoice shows both options. So, the car as built, would have had a

Your car would have come from the factory with a 3.54 Dana rear. I don't have my white books in front of me, but would imagine that the D56 is for a car that came from the factory with a 8 3/4 rear and you checked off the box to upgrade to 3.55 ratio. You couldn't have optioned your car with D56.
3.54 in Dana's and 3.55 in 8 3/4's, just the way each were made.

My invoice shows both options. So the car, as built, would have had a 3.54, even though the D56 option is on the invoice?

 

[4speed68rt]

Please show us some pictures of the car, the rear end that's in it and the invoice. We dont even know what kind of car you are talking about. Thanks

 

[33 IMP]

Your invoice is a misprint/mistake.
A33 is Track Pak with 3.54 (Dana 60)

So, your car with 440/4sp with a Dana is correct, and the Dana automatically specified with a 440 four speed at that time. An 8 3/4 was NOT available for a 440/4 sp.
If your car is a lynch road build, fender tag should show 596 or 597 depending on disc or drum brakes.

 

[69Coronetrt]

My car is a 440 4-speed. If the A33 was an added option, would it make sense to build the car with the D56 option? It doesn’t seem like you’re adding anything useful?!?

Coding quirks exist and you found one of them. What you are showing is normal and to be expected.

For model year 1969, both A33 Track pack cars AND A36 Performance Axle package cars code D56 3:55 gears on invoices, window stickers and broadcast sheets. As there is no 3:55 ratio gear assembly available in the Dana 60, your car came with the standard 3:54 gears. This is just not accurately coded on the paperwork.

All is well.

 

[33 IMP]

Please show us some pictures of the car, the rear end that's in it and the invoice. We dont even know what kind of car you are talking about. Thanks

He's got a 69 GTX.

 

[ericisback]

Coding quirks exist and you found one of them. What you are showing is normal and to be expected.

For model year 1969, both A33 Track pack cars AND A36 Performance Axle package cars code D56 3:55 gears on invoices, window stickers and broadcast sheets. As there is no 3:55 ratio gear assembly available in the Dana 60, your car came with the standard 3:54 gears. This is just not accurately coded on the paperwork.

All is well.

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Thanks so much. Super helpful!!!!!!!!