DaRock, I'll go with careful wood selection, too. I've also got engineering books, with all the vectorial stress analysis tables...but their value is dwarfed by looking over just ONE proven model aircraft blueprint for whatever your interested in. Neither book of mine has a chapter devoted to balsa though.

The previous photo is of the SuDoKoi designed by Tom Stryker for Morris Hobbies, a .45 to .60 sized 3D profile. Awesome plane, a pioneer of 3D flight for the masses.

The plane pictured here is closer to the "Granderdog" you speak of. It was designed by Norm McFadden and campaigned for several years by Norm, Bob Carver and myself.
10 ozs without engine, AMA fast Combat with a 2HP .36.

BTW, these planes did have horizontal grain webbing, but it's main purpose was to give the foam LE gluing surface. These planes exploded if anything didn't go as planned, so there wasn't much point in any heroic efforts as far as shear webbing goes. The average combat match lasts about 20 seconds. I built them in batches of 6 to make it through a 2 day contest, because win or lose your plane could be toast.