It is my understanding that a mix of units was used. I do not know how much metric was used in the design of the engines or rockets, the construction was largely done in SAE units because that's what the aerospace industry was tooled up for. It is my understanding that calculations were done in metric but converted and displayed in nautical miles, feet, and feet per second for the crews who, being US aviators were accustomed to those units. The crawler transporter's fuel economy is measured in gallons per foot.