400 spine means the shaft has a spine deflection of .400

deflection is measured by hanging a 1.94 pound weight from the center of a 29 inch arrow shaft. The shaft is supported at each end 28 inches apart.

So there is a support 1/2 inch in from each end and a 1.94 pound weight set at 14.5 inches (center).

If it is labled as 5575 means 55 to 75 pond draw weight or a 7595 would be 75 pounds to 95 pound draw weight.

Yes those are the correct spine for you.