You should get .5"-.75" back with an empty tank, i would get 2 OME trim packers for the driver side if i were you, unless there is an underlying problem i am not aware of. The tank is on the driver side so there will usually be lean towards that side (except mine, that leans the other way), so if you put the coils on the wrong side then the passenger side will be slightly stronger then the driver side which wouldn't be a big deal except for the fact that the drivers side has 16+ gallons of gas on top of it, and the drivers sits on the driver side, except for IanB.