The only company that could build a hydroelectric dam with only their equipment. They built crawlers and scrapers, Turbines and alternators, transformers and power handling equipment. No other company was capable of single sourcing such a project,
A series II D21 came to our farm in 1966. Factory turbo and factory duals. It was the main tractor for several years. I bought a 1370 Case in 1973, to run along side of it. The Allis was more tractor, even though specs should have favored the Case. I believe most of the D21s had the smoke screw tinkered with. The old Allis still has a place on the farm. It is the auger tractor. We doctored it a bit, to have remote start and shut-down and a remote controlled hydraulic remote.