To build our necks, we bought a 6' maple 1" x 3". The wood was plain sawn. Quarter sawn wood is ideal, but plain sawn is okay as well.
The neck needs a 15 degree angle for the headstock to balance the tension on the neck (undesirable) and downward tension on the neck (desirable).
For the length of the neck (including the headstock), we cut out a 22" segment of the 1x3. For the angle, we glued a 6" segment of 1x3 maple onto the 22" piece, and cut the angle into the block. Here is where the neck is at the moment. (Don't mind my feet)
We'll be cutting the truss rod slot into the neck this week.