I am quite sure there is nothing that you can buy for the 4.2 for cold air intake. This is a mod that primarily used for fuel injected vehicles. I have thought about the same thing for my 4.2, which is now fuel injected. I have considered building a snorkel to kill two birds with one stone. You are only limited by your imagination, you should be able to build something to work. It doesn't have to be anything elaborate. You could get some PVC pipe and throw something together.