94 k-1500, discovered about a 3" vertical crack in the driver's side plastic radiator side tank right around where the upper oil cooler line screws in. Leaking pretty bad. I can get a new rad at NAPA in town here for $185 but have heard about plastic repair kits. Those things work? Since we use the Burb for towing a TT in the desert and over mountains am a little concerned that the plastic patch might fail. Any thoughts or experience with these kits out there?