Your biggest challenge is going to be redoing the cowl in front of it as they are very different from the later dashes. There will also be some issues on the where it connects to the structural steel behind the radio console. This thread will help you with the cowl problem;
http://www.mgexperience.net/phorum/read.php?1,1172895,1173515#msg-1173515
Alfred, Maine
63B Waiting for resto
63B Donor
67B Ours
73BGT Mine
73BGT Hers