done both mine , just tweekd the pump and removed the cat, the smoke screw 1/4 turn clockwise the diaphram under it about the same you may have to back it off a little iff it smokes too much, under the diaphram is a star screw alter that about a 1/4 clockwise too, mark everything so you can turn it back iff you need too. have done a freinds defender too he had a larger intercooler and pleased with it. just remember iff it smokes. smoke = unburnt fuell = higher e.g.t. so be carfull and dont over do things. after all its a landy, they aint designed for speed....alan