My data says the deflection is.487 and if I devide that deflection into 26 I come out with woodies that would be 53.38#. Which I have shot alot. so I would say yes they are around 50# spine depending on point weight. I shoot from time to time heritage 150's with 145 head out of a stewart longbow and they fly great, weigh around 530 grains 28 " arrow. The Stewart is center shot though and those types of bows are more forgiving of spine. I'm sure they will work you just have to mess with the point weight, your bow will be more particular about spine. The other manufacturers arrows should perform in a similar manner.
Hope this helps