Hello, I am trying to figure out which air filter system to use on my 71 chevy truck. I put the 5.3 in it. I could use a 99 & up air box and make up a 4 inch pipe to connect to the motor or go with a complete system. On a budget. I have plenty of room on the front passenger side. What about modifying the stock box for a ram air type system? I hope to get some advice as I have had not much interest in my past posts. Thanks, Alan