if u have F18, easiest to swap is always the same series engine as they have (cant find word) same thingy that will match gearbox. when u swap for H22, u have to swap gearbox and LSD too. and i dont recommend u to swap for B16. i was recently fully loaded with 5 persons in my car and although i have F20, when overtaking engine was kinda like "oh what a heavy load". and imagine that with B16. when u would have B16 and fully loaded... imagine that fuel consuption... i bet i would have better economy in F20 than u in B16