I'm not familiar with the ATX spindles however when I was looking around for steering arms to use on my ridetech spindles I found a few that could be made to work. The top one is a regular GM steering arm and the other 2 are made by speedway. They will need some work to fit a GM spindle. They are designed to be used with metric impala spindle they sell, bolt spacing is the same however the bolting surfaces are different and would need to be shimmed, also not sure if they would clear the top of a ball joint stud.
