Got a Big Block Question?

[jover]

Hey just bought a 454 Big Block (casting #14015445) this weekend for my 68. My question is does anyone know where I can find HP rating from the factory for this motor and on the block it is stamped Hi Perf, exactly what does that mean as far as why did GM stamp it on some blocks and not others. Also the heads that are on it are casting # (14081045) stamped Pass which I presume means passenger, and its got guide plates and studs. What size valves would they be? Also how many CC's would these heads be? Your help with any of these questions would be so helpful. You can email me at jirwin59@usadatanet.net. Thanks JoAnne