[84GMC15tepside]

They did come in diesels but those I think were iron cast (and I think the 4x4 versions were too). My truck came factory with the tranny and its aluminum. It was behind a 250 inline and now will be behind a 350. If you are looking for one/if you find one, make sure you get EVERYTHING included... shifter, rods, rods-to-transmission brackets... No new shifter can fit on it the A833... has to be factory. Also, I think that the iron case had a differently designed bellhousing than the aluminum case... Here are some pictures.