Why don't they leave them 427's?
I mean after all, if 427 is good, 480 something MUST be better, ie, bigger is better is the American way!
But actually the original bore\stroke numbers of the 427 side oilers were carefully thought out and chosen for specific 'race' inspired reasons. The basic equation of a 'good race motor' has ALWAYS been BIG bore in relation to a SHORT stroke. Porsche and Ferrari are two examples that to this DAY employ that reasoning. Short stroke means higher rpm potential. Higher rpm means more HORSE POWER while sacraficing 'torque'. While some say 'torque' is what wins races, I disagree, it's HORSE power that wins races, and history is filled with example after example.
Todays small engines (Honda and other 'ricers') are based on horse power, you simply can't get BIG torque numbers out of a tiny motor. 'Torque' is what the driver FEELS when first accellerating, it's TORQUE that pushes you back in the seat and makes you 'feel good'. 18 wheeler trucks have MASSIVE torque, but there kind of slow on the race track...
You want FAST? Go small block, short stroke BIG bore. You want 'feels awesome' BIG torque? Go with a LONG stroke, big cubes and smaller bore. To each his own. A 427 compared to a 500 plus incher is a much smaller AND POTENTIALLY faster motor!