This car being more powerful than 512BB has higher top speed, but 300kph is also very hard to believe.
As F355 posted before it has 380 PS and 432 Nm.
Here tested top speed is 290kph - http://www.monteverdiclub.com/images/rccount.jpg
Year of introduction was 1973, in 1971 they just showed concept, which was different to production model.
Ferrari 365 GT4 B/B specs
|Curb weight||1554 kg (3426 lbs)|
|0 - 40 kph||2.0 s|
|0 - 80 kph||4.5 s|
|0 - 100 kph||6.2 s|
|0 - 180 kph||18.5 s|
|1000 m||25.8 s @ 203.0 kph|
|Est. 0 - 60 mph||5.9 s|
|0 - 100 mph||14.3 s|
|Est. 1/8 mile||9.9 s @ 84.5 mph|
|Top speed||303 kph (188 mph)|
|Engine type||V12 n/a|
|Displacement||4.4 l (269 ci)|
|Power||360 ps (355 bhp / 265 kw)|
|Torque||410 Nm (302 lb-ft)|
|Power / liter||82 ps (81 hp)|
|Power / weight||232 ps (229 bhp) / t|
|Torque / weight||264 Nm (195 lb-ft) / t|
|Transmission||5 speed stick|
|Layout||middle engine, rear wheel drive|