A 4G63/4G63T swap in any Tiburon requires extensive modification and fabrication, it has been done only a few times worldwide, and is often a topic of discussion in Hyundai forums of all kinds. It actually comes up quite often, here is one from two days ago
http://hyundaiperformance.com/forums/topic.php?t=75579
http://hyundaiperformance.com/forums/topic.php?t=75579