Preheat oven to 375°. Stir together salt and pepper.
If applicable, remove necks and giblets from chickens, and reserve for another use. Pat chickens dry. Sprinkle 1/2 tsp. salt mixture inside cavity of each chicken. Rub 1 1/2 tsp. olive oil into skin of each chicken. Sprinkle with remaining salt mixture; rub into skin. Place chickens, breast sides up, facing in opposite directions (for even browning), on a lightly greased wire rack in a lightly greased 17- x 12-inch jelly-roll pan.
Bake at 375° for 1 1/2 hours or until a meat thermometer inserted in thigh registers 180°. Let stand 10 minutes before slicing.
This is my go-to roast chicken recipe for over a year now. You can easily add other spices such as thyme or sage to the salt mixture; or stuff the cavity (discard after cooking and garnish with fresh) with onions, apples, or rosemary and lemon for a variety of flavors. Definitely use kosher salt. Wonderful that it makes two - debone one and you have cooked chicken for another recipe.