I've often wondered why the army didn't at least approach, if not Grumman, then another Naval company and find out how they got such terrific range in their aircraft. I can understand them being hesitant to put the Merlin in the Mustang as it was a different country's product but was there that...
Just purchased an audiobook from iTunes entitled WWII Airmen: Amazing Accounts of Airmen Recorded During the War. There are interviews, radio broadcasts and recordings from the aircraft during the mission. It was only $3.95. Two hours. I love stuff like this!