Is this valve body different?

I recently had a transmission failure and decided to rebuild my whole transmission, and now I'm starting the valve body. When I took the transfer plate off There was only 6 steel balls instead of 7 (circled in red is where I think it was missing) I don't know if there was a shift kit put in this transmission or not, and if that would change that. One of the larger balls also fell out and I figured that one went to the spring in the corner, I put it there for the picture.

I have also been using the ATSG book during this rebuild but for the valve body I switched back to my 1969 dart manual (figure 52) because it seemed more accurate. They show two different valve bodies with two different steel ball locations. However, I don't know the year of the transmission, and if there was a shift kit installed. How could I tell if it has a shift kit and should I get a ball and put it where one is missing or is it not needed?

Thanks again for all the help and let me know if you need any more pictures or information.