accelerator bracket 70 chevelle/L78/LS6

[P.J.]

I am restoring my L78 70 ss and have run into a mystery reqarding the accelerator bracket for the holley carb.I have dicovered that there aparently were 2 brackets installed with the part number 3972619.I am enclosing a pick of both brackets. One of the brackets is different only at the locking tab the rest is identical.I have piks of both brackets that were installed at the Atlanta plant, one in a car built in April 70 and the other built in Aug 70.I also have pics of a bracket from a car built at the Kansas City plant in Nov/69. What bracket was installed in what plant? your help would be apreciated with picks and a build date if possible
thanks
Peter