Ken, I'm no expert but I think it would be more likely for your car to go either way regarding an aluminum T-10 or cast iron T-10. My car has the original cast iron T-10H with the original M-series close ratio gears that the aluminum T-10M's had. I'll add this for the real experts: does anyone know about when the transition from aluminum to iron T-10's was? Dave 6S1757 In a message dated 2/14/2005 11:13:57 AM Pacific Standard Time, mustangmann@charter.net writes: > Just thought I would pose a question to the experts! > Does anyone know when Shelby switched from the aluminum T-10 trans. to the > Ford Top Loader? From what I have been told in the past, my car could go > either way. > Always appreciated! > Ken > 66 #745 >