The LS3 motor does not have a fan so you have to install a radiator with electric fans. We went with a radiator from Be Cool
http://www.becool.com/ and these guys were very helpful and knew exactly what we needed. Their radiator is already set up for the fans to kick on at 210 and off at 190 which is the temperature operating range for the LS3. They offer polished but we just went with natural finish.