A homemade one out of steel would be bad. Steel gets hott and would make the air coming in warm which is bad. A PVC intake is bad as well. sharp bends and PVC makes toxic smells if it gets too hot or melts. Best bet is to just spend 30 bux on a cheap intake and then buy a K&N filter or use stock tubing and air box with K&N crop in and remove resinator and pipe that goes over the rad and run a cold air hose from the air box to where the resinator box was. If you get a steel made pipe intake at least put some heat wrap around it.