Pad Change Problems

Having finally toasted my front pads at a track day yesterday, l decided to fit new pads and disks today. All seemed to be going OKish but l am struggling now. l think the piston is back as far as it will go (using a G-Clamp to push it in). But l can't get the caliper to drop down over the pads - it just won't accomodate them. Am l just being a wuss and not screwing hard enough (ooer)?