Based on dyno info I've seen you are making a performance step down. The Donaldson flows more air than any other filter, just look at its surface area. Also if you want a bottom breather, TPIS sells the kit to make the Donaldson a bottom breather for less than $80. As far as the air bridge, it is not necessary unless you have a stroker motor with a ported TB. Doug Rippie is of the same opinion on this. This is of course just my humble opinion, although it is a learned one. /phpBB/images/smiles/icon_wink.gif