Bite the bullet and buy a new radiator. It is 14 years old and sat for most of its life. The thing is clogged. Just to save you from having to replace the fan clutch in the near future replace it while the radiator is out. Contrary to popular (on this forum) belief a radiator is not a part that lasts for a lifetime. If you are overheating in 85 degree weather the rad is incapable of shedding any heat. Also make sure your antifreeze solution is 50/50 to 60/40 not 100%. Prior to replacing the radiator run a descaler/cleaner in the cooling system but make sure prior to installing the new radiator that everything, including the heater core, gets flushed clean. You should also remove the block plugs to get all of the sediment out of the bottom of the block.
Randy
