I've found that sinewing a bow longer than 60 inches, not only are you using alot of sinew, the outcome is not what you expect. BUTTTTTTTT........................
Hey, give it a try and let us know. If you can, shoot the bow before you sinew it, then do the sinew like you want and then let us know the diff. results. Is the mass on the limbs worth the work or would slightly bending the limb tips have worked better.
Good Luck,
Frank