Throttle cable detent pulls out of adjustment at wide-open throttle. This problem occurs with Edelbrock carburetors in use with most GM transmissions with cables. This is typically caused by inaccurate geometry of the carburetor linkage plate.
In order for the TV to function properly there must be a specific degree of movement of the throttle valve linkage between closed and wide-open throttle. There should also be a specific distance between the pivot points of the throttle valve linkage and the carburetor linkage. When either of these two distances are greater than the spec, the TV cable will be pulled out of adjustment.
The TV cable corrector AS5-05K kit adjusts the geometry of the TV linkage to prevent the TV cable from being pulled out of adjustment at full throttle. A quick and inexpensive fix for any transmission with a TV cable.