The Eagle "kit" consists of high quality H-beam rods, light weight forged pistons, plasma-moly rings and Clevite bearings (we sub in Federal Mogul mains, as they're 3/4 groove instead of "full groove"). While some of this MAY sound like "Greek", it means the stuff is among the highest quality. The crankshaft is cast steel, rather than forged steel. At the power level you desire, this is not an issue. The cast crankshafts are known to withstand 700 HP all year, and 800 in some applications. At the 500 HP level, they'll be fine.
Thanks for the vote of confidence from 440GP69. However... We DO believe the later blocks are fine until the 600 HP line is "crossed". The larger displacement DOES raise the compression significantly. The 6X heads are quite well suited to this application. Only a "clean-up" cut is required to get to around the 9.2-9.5 range. No reason to "press the edge" of compressoin for a pleasure-mobile. If it were a "class racer", that would be a different story. By keeping it under 9.5:1, you can usually count on fuel to NOT upset the "mix".
We (CVMS) tend to emphaisize more the final power output and drivability, rather than flow numbers and other indicators of "potential". Flow numbers are no guarentee of power, but just another indicator. We also believe too much is made of "cnc" porting, as a marketing tool, and also, no guarentee of performance. We use good old fashioned "work" to get heads where they need to be. Since every application is different, it's unreasonable to think a "one size fits all" approach is better. A professional head porter doesn't need a machine to maintain consistency. Typically, we spend about 10 hours on the porting bench for a real strong 461 application (500-plus HP).
Jim
www.centralvirginiamachine.com