Quote Originally Posted by EricGTP View Post
maybe I'm missing it but can you technically put a 4t65e non hd in a GTP and expect it to be reliable. I know gearing is different and it it has a harder input shaft
Non HD and HD have the same input shaft. You can put one in. Many guys do top swaps on non HD trans and they can last reasonably. The biggest variable is how your foot treats the throttle.