Depending on your scrounging skills, you can put together an "off road"/ "industrial" cold air induction set up for well under $50.00. Some off road filter canisters have a "inlet" neck as well as the discharge neck and the existing hole in the core support is a good location to pick up cooler air, 'specially if you find the later model plastic "turn lock" adapter for the factory snorkle hole, found on lots of forrestry dept. crew cabs and suburbans. (or you can cut a hole in the existing plastic difuser and RTV in a piece of 3 in.thinwall PVC)
Don't overlook the rental yards in your area,as well as the state and county garage's (a box of donuts goes a long way...) they can be a good source for odd parts and used stuff from the sluice boxes, hydro mining rigs, and portable generators. (I lived in Grants pass, back in the '80's and built up a monster scrounging network.) Happy hunting.
RED (Fabricobblers rule)