Spindles Needed 14" For A-Body

I have the SSBC A153 kit (the non power disc brake conversion) and it will accept only some of the 14" wheels and the 15" wheels. They don't seem to specify which ones. I called them, talked to two different techs and, to be honest, neither one seemed very well versed in these kits to give me a very definitive answer on exactly what I need to complete the conversion on my front end. Oh boy. I feel rather deflated, tbh.