I have a 55 Tbird with auto trans.    I have a 57 intake manifold.   I will use an Edelbrock carb.   Can I retain the stock linkage and fabricate the arm from the bell crank to the carb?
Does anyone have any pictures of what they used for linkage?

I don't see why you cannot use the stock linkage although not familiar with the 55 linkage.  It would seem that the only thing you may have to change is the rod going to the carb.  I remember from another person who made a similar change that the height of the spot  where the linkage bolts to the intake is different than a 55/56.  If it is shorter, you may have to add a spacer.
If there is a problem with the 55 linkage, you may have to go with a 56/57  setup
The only other problem that you may encounter ( I don't know) is a different bolt pattern on the 57 manifold for the linkage to bolt to.  In that case, aftermarket or 56/57 linkage or an adapter made  will be needed

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I have a 57 B manifold.   I thought the bolt pattern for the bell crank looked (just eye balled it) a little different than the 55.  Hopefully I can modify the holes to match the manifold.  I am having the manifold blasted and opening up the intake flange, so I don't have it here to check
If I can retain the existing linkage I may be able to use the stock rod (see picture).   OR just replace the rod that connects to the carb, with a threaded rod.    What is the purpose of the spring loaded rod that connects to the carb?  The spring expands when it gets to the end end of travel.             

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I never could see the reason for the spring loaded piece.  Some one here might know.  It was dropped for 56 and 57.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

This is just a guess but I think it allows further travel of the kick-down linkage beyond wide open throttle for the passing gear down shift or the overdrive kick down switch which ever may be appliable.

64F100 57FAIRLANE500

Maybe also to absorb the shock wear of aggressive drivers frequently mashing the carb/linkage mechanism so forcefully to its furthest extent (?)

6 VOLTS/POS. GRD. NW INDIANA

When I floor the car I can feel the extra movement required to move the kick-down is coming from this device

When I floor the car I can feel the extra movement required to move the kick-down is coming from this device

Have someone operate the throttle linkage (engine off) and see what the rod (spring) does.

The MPC calls for this rod for both ST and AT.

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