does anyone know what "special" tools are required to work on the interior parts of a transmission? i have a 1997 Z71 silverado with a 4l60 in it and my transmission just went out but i have a transmission thats interior "guts" are in perfect condition but have a crack in the case, so im going to try to take the good guts and put them in the good case, ive been told it requires special tools, does anyone know whats required?