A little info on the Detroits-
Detroit Deisel was a division of GM, with design and testing of the 2 stroke engine stating around 1932, with production starting in '35. The original use for the engine was deisel locomotives. GMC offered it in trucks in '37/'38. Chevrolet didn't get a deisel until the '60s. Detroit Deisel engines were manufactured with both iron and aluminum blocks. They were also sold as Grey Marine engines for use in Navy vessels.
The numbering system refers to the number of cyliders and the displacement of each cylinder, example-6-71= 6 cylider/71 cid per cylinder, 426 cid total displacement. These engines range from the 2-53 used in John Deere 420/430 to 12-110s that are usually found attached to hospital generators. This is also where the numbering for the aftermarket superchargers came from, as many early rodders used blowers from these engines.
