i used to do these mods for my past cars. as a word of advice make sure you guys replace or clean them often. they are not meant to be used and left there for a longer period of time than oem. in most cases they need to be replaced or cleaned even sooner and more often than the oem units.
for me i just buy oem parts and replacement more often then recommended. i do notice better fuel econ when i do it this way and less debris in the intake tubes.