The engine is a 450 hp Wright Whirlwind R-975
overhauled in Georgia by Wright guru Mike Connor.
Originally, the engine fitted to the Travel Air 6000
was a 220 hp whirlwind of the type used by Lindbergh.
Then the Travel Air factory developed the S6000B
by fitting the airframe with a 330 hp Whirlwind and approving it for floats.
The "440 Wright" (actually 450 hp with a propeller that will let it develope full rpm)
went on in 1946 when the wartime engines became available after WW2.
