I think you are way off, saying an engine is an engine. yes they have the same concept of running, with pistions, cranks and rods, and a fuel with combustion. The diffrence is engines that are in plaines are designed to withstand the higher air preassure, I'd bet your mechanicle injection ajust's in major ways to take the high preassure and make the engine run correctly at the high altitude, spark curve and all of that changes with the altitude, you tune a car with a distributor at the altitude it will most see, cars with coil packs and EFI constantly change the spark curve with the altitude changes, as it notes the changes in preassure. I doubt that a production ECU will have ajustments for more than 10,000 feet, you would need to make a custom program