The 1JZ-GTE was only used in the MKIII Supra from '91 to '93... If it's '94 or newer it's most likely from a Soarer in which case you will may need to swap components such as the oil pump and oil pan, subframe and motor mounts and I'm not sure what else.
The swap from a 1JZ equipped MKIII to a 7M equipped MKIII is covered in the FAQ section:
http://www.toyota-supra.info/forums/...pic-heavy.html