The Swiftfire was a one-off modified Swift with a 450-shaft-horsepower Allison 250-B17C turboprop and design cruise speed of 345 mph.  Although the project never came to production, (and the Swiftfire has since be converted back to a more common 210hp Continental IO-360 engine), it has been noted by many aeronautical engineers that Roy Lopresti's Allison installation was the best looking conversion ever for an airplane not originally designed for a turboprop engine.

Oh... what could have been.

Of course, you'd have to think that LoPresti
might be persuaded to make another for some Swifter with lots of




What the Swiftfire used to look like...