Also to explain the theory behind this, At the time AC needed an efficient 70 to 115 hp power unit. They had a D262 6 cyl to work with. Harvey guys developed a direct injection head for this unit, I saw one, but the bottom end would not hold up at 100 hp for the engine life needed. The 6 Cyl 301 2900 would but was too big for powerunits at 70-90 hp as utility tractors were sized for 4 cyl size and also did not have the economy needed. Now enter a sidebar - tractor pulling was entering the multistage turbocharging and they found that unless they dropped the compresssion ration to about 12 to one that bad things happened at high boost to the insides . Therefore the engineers found that they lost no horsepower by lowering the comp ratio and in theory gained engine life. One substituted incoming boost pressure for compression pressure. The only problem was not enough heat at cranking speed to fire off the engine in cold weather. After introduction the feedback came loud and clear - make them crank. Thus the increase in comp ratio - now back to 16something to one and smaller hole inj tips and the dual air heaters and ether inj. Also there has been no decrease in eng life noted by all this as well. These engines were used in K2-F2 880's-6060 6070 6080 Barko log loaders- 706dForklifts 715D backhoes Gen sets, Water pumps, and probably a bunch more.