http://www.grandamgt.com/forum/showthread.php?t=5601
You need lots of custom tuning, all new brackets and mounts. Custom fabrication and lots of other stuff. A 4t65e is for performance for our cars really. If your not planning on building it, just get a 4t45e. But be sure to get one with the same Ratio, aleros are. 3.05. Ones out of gase's are the same but grand am gt's are 3.29 and would require messing with the shift points and stuff.