Your better off to install a simple shift kit. Unless you're a "hardcore," drag racer type, a full reverse manual valve body will just keep you busy shifting. I have a TCI full reverse auto/manual valve body sitting in a box in my garage. It works either way. You can manually shift with it or if the kick down is hooked up you can use it as fully automatic. That type of valve body might work better for you. Best of both worlds. Check with TCI and get an opinion from them.
