You can't really build a wooden bow to weight by dimensions-every piece of wood is different. You have to start tillering and work it down until it's the weight you want. I would start with a piece about 62"-64" long, cahse a back ring, then lay out the width about 1 1/2" wide at the fades to 1/2" or less tips, and lay out the beginning thickness taper at a little over 1/2" at the fades tapering to around 1/4" at the tips. (For a stiff-handled bow,that is- if you want a bending handle, make it about the same length or longer and 1 1/8" -1 1/4" wide center to midlimbs tapering to 1/2" tips.) Get it bending good first, then reduce the weight to where you want it. My wife has a locust bow I made that she shoots a lot, it's around 28# @ 26", and those are close to the dimensions, leaving some extra thickness for tillering, of course.
