I bought the open air filter with the paper element and am very pleased.... the cost was 29.99 and It was worth every penny.... I didnt figure it would do all that much.. But the first time I drove my 88 TBI 318 with it on I could definately tell a big difference.... It has better throttle response the exhaust at 2 thousand rpm's went from nice to annoyingly loud and over 2500 rpm will run you outta the cab..... It has that nice whistleing sound also that i like... Also you will need a one inch tbi spacer so it will set high enough to clear the IAC motor.... I will get aK&n filter and put in as soon as i get the extra cash and see if that makes an even better difference....