I have heard of guys re-using the stock 4.0 radiator, and that it cooled plenty well enough for the 5.0, but I have no personal experience with doing that. Probably I would want the 2-core one aka "SuperCool" in Ford's jargon -- (I know tow package 1994 1st gen's had it) at least though. Also, some have had to move the rad slightly forward for pulley/fan clearance, which may involve more significant mods like to the core support etc. Hopefully you won't have to do that.