For a typical 70's early 80's race bike, the seat post should be out of the frame about 4", the 100-120mm stem should be out no more than 2", the ends of the handlebars should be parallel to the top-tube, the brake levers should be centered on the hooks, the saddle should be level with the top-tube or pointed up slightly. Now the bike looks right so it must be comfortable. Oh and keep the brake cable housings nice and short, as long loopy ones spoil the look, which can be very uncomfortable.