1st to 2nd 6500
2nd to 3rd 6200
3rd to 4th 6000
4th to 5th 6200
That's what I calc, assuming you have a T-5. It's like that becuase your torque curve extends so high. That's why you want to stay away from creating a high rpm power band if you don't plan to build a motor that can rev that high.
Still, it's all theory. It's correct but it's idealized. There are other factors that come into the picture and you will have to experiment to find the best shift point. The calcs just give you a good starting point.