Here are some reported 454 specs from the data base:
Horsepower 330 hp at 4200 rpm
(compared to 300 hp at 4000 for the 427)
Maximum Torque 440 ft. lbs. @ 3500 rpm
(compared to 438 ft. lbs. @ 2900 rpm for the 427)
8.5:1 Compression
(compared to 8.9:1 for the 427)
In addition, here is a great fuel consumption thread for these big block motors:
http://www.network54.com/Forum/424840/message/1150656733
Regards,
Paul