Sure this isn't new to everyone - have a look on the startech website, on the Crossfire pages you will see their V8 6.1L. Forget about $25K though.

From the site;

The engine bay of the new coupe turned out to be large enough to accommodate the STARTECH V8 6.1 increased-displacement engine, albeit after some modifications. Power is transferred to the rear axle via an electronically controlled five-speed automatic transmission and a custom-developed locking differential.

The STARTECH V8 6.1 engine delivers 426 hp / 313 kW at 5,400 rpm and produces a gigantic peak torque of 621 Nm at 4,100 rpm. Thus equipped the two-seater coupe turns into a purebred sports car with extreme performance potential: The STARTECH Coupe V8 6.1 takes just 4.7 seconds to accelerate from 0 - 100 km/h. Top speed is 300 km/h.