help?what is this 4 speed

thanks for the help everyone but still confused this tranny has the 5.125 tb shaft aluminum case iron tail shaft this suggests it 2 be an od tranny right?doesnt have levers on it so cant tell if one is mounted upside down have side cover off how can i tell by looking at the gears any help sure be appreciated

Do you have a digital camera? Post some pictures if you can...that would help a lot. If not you know it's a 4-speed right? If it all looks good on the inside I would go ahead and run it. Unless you are thinking about getting another one or something.