go through with 9.5s and your bound to fail.
also , id just replace the exhaust with a stock system from the cat
thats what i did on mine and i passed with flying colours
your also going to have to do more work on the vehicle to make sure everything else is up to scratch as they will go over the whole car.
also make sure you have an english tyre placard on the vehicle (usually affixed on the drivers side door jam)
chuck stock wheels on , stock exhaust and stock suspension in and you'll pass