A friend of mine recommended that for first flights after refurb or with newly overhauled engines that on takeoff after you are off the ground that you drift right of the runway. This makes the "impossible turn" - a 180 to land back on the runway - much easier to do, since you are making a 'U" turn rather than a complete circle. In the case of that P-51 with engine failure he had just enough runway to land and get stopped, so drifting right would not have done any good.
A friend of mine was taking off in her Ercoupe, demonstrating what she called power surges to her A&P. But this time the surges seemed to be worse so she chopped power and made a "impossible turn" - that airport has parallel runways. She made it down but hit three parked airplanes and totaled her own, but without injury. It turned out that the throttle cable was not well supported, leading to it flexing and transmitting that motion to the carburetor, causing the engine to go "RRRRR..rrrrr...RRRR," There was nothing wrong with the engine; it was simply as if you were working the throttle in and out slightly, but she chopped power needlessly as a result.