I also had what seamed like a lot of space between crossmember and sump. I,m using a ute crossmember and I heard somewhere that they mount an a15 higher.....I would think about 10mm-15mm space or less would be what the standard engine would be fitted at.
Remember that my mounts are aftermarket and made from nolathane, very simple in design, all they are is a piece of nolathane with one bolt running through the centre....will put a pic up in the next couple of days if you want.