Just to throw the cat with the pigeons, I know the LS V8 is a good solution but why not a BMW V12. Stay with me here fellas. The M73 5.4 V12 is a light weight all alloy, very compact motor that was designed to make big torque at low revs. To power the 7series luxury machine along and be capable of high Autobarn speeds. It is single cam and each head has its own separate ignition system and injection. It is designed to have limp home of allowing one bank of cylinders fail and it will continue firing the other bank. Due to a 60 degree V12 they are compact light and smooth. A much nicer solution on harmonics for direct drive or a gearbox. They are amazingly smooth - such you can rest a Aussie 50 cent on its side and rev the engine. _I have done it on my brothers V12, and 340hp. Correct the cams to suit, a higher compression ratio and that 300hp is attainable at 4,000rpm. And the sound of a healthy V12 is glorious. A version of this engine with twin cam heads powered the Maclaren F1. Later versions of BMW v12 6.0 litres and twin turbo and can be made do very big torque and hence power at prop friendly speeds. They are cheap to buy from a wrecker and easy to get parts for. A direct drive Bmw V12 could be built just right for a similar price as the new LS. And would be great on the right machine. The harmonics are the thing, just sounds right.