The 3,057 kw (4,100 ehp) XT34-P-2 was developed originally as a dependable simple-cycle turboprop engine for use in high performance, long-range aircraft. It was intended that it might later be developed into a free turbine engine. A design contract for the T34-P-2 was issued in 1945, and amended in 1946 to continue development and component testing. The first engine was tested in January 1948.

The T34 turboprop engine first flew in September 1950, installed in the nose of a B-17 flying test bed, and the four-engine Boeing KC-97J, which survived as the B-377 Super Guppy, was its first application. The Air Force then selected the P-3 model for the Douglas C-133A Cargomaster, also having four engines.

Later development resulted in the 6,816 kw (9,140 ehp) XT48-P-2, which was considered for the dual engine VP-HL, a heavy, land based naval patrol aircraft that eventually led to the well known four-engine P-3 Orion.