mazda has used a 4 and five speed over the years in their cars and pickups that use a clutch housing that is held on with 8 bolts. it was so the same transmission could be used between the RX series and piston engines. later when they started to use ford engines in the ranger trucks and also some of the aerostars they had a housing that fit the 2300 (pinto) style motor. weather Mitsubishi or Mazda or Toyo Kogyo or Jatco built it I have no idea, but I know theyve been useing that same design since 1974 with the cast aluminum bottom cover. and the ones with this cover have clutch housings that bolt on and interchange with some other applications incl. some mitsubishi trucks and maybe some others. wow I did not intend this to be this long! hope this helps some.