It looks like I goofed on the yeast. It should be 3 Tbsp and not 4. I usually round up a little though.
I actually round up on the water (6 1/2 cups instead of 6) and round down on the flour (12 1/2 instead of 13).
I think the hardest part of the recipe is actually measuring out 13 cups of flour without losing count. It used to be worse when our kids still lived at home. I think they messed with me on purpose, so I would always repeat the number until I finished. If the kids came up and asked me a question, I would stare at them and just keep repeating "eight...eight...eight...eight..." until they left me alone.