The Kawasaki Ki-91 a japanese project for a heavy strategic bomber to match the B-29, with prototype nearly being completed,however a bombing raid in early 1945 destroyed the prototype and most progress on the plane.
Stats:
Capacity: 8
Maximum speed: 580 km/h (360 mph, 310 kn)
Range: 10,000 km (6,200 mi, 5,400 nmi)
Service ceiling: 13,500 m (44,300 ft)