To get that grab in the cork 7, I would practice doing a tucked in cork 7 with an ironcross to get the feel first (a few times). Once you are comfterble with that, practice doing the same thing but look at your cross in the front to tell where your tail is in the back (so you dont have look back for the grab and slow down your spin). Once you know where your tail is in the back, reach out and grab it. But remember pop off the jump, set your rotation, cross your skis and then find the grab. You have to be patient with the grab.