The magazine articles are very interesting. However, I think they oversimplify the builds and the work required to get the engines built properly. I'm in the middle of my 408 build right now. If I had to do it again I would go with a stock 360 or put down the bucks for better components such as a Callies crank and some good rods and pistons, perhaps JE. No machine shop I spoke with recommended bolting on the Eddys out of the box. They always recommend cleaning them up and checking the valve job at a min. Some of the magazine articles say that they bolted them on without even changing the springs for a roller cam.
That said I think my combo should be good for 450 hp if I can believe the magazine dynos. It's a 408 with 10.5:1 compression, file fit rings, Probe pistons, Eagle rods and crank, Eddy Magnum heads, 1.6 Comp Cams Pro Magnum rockers (Chevy stud mount), Comp Cams XE274 cam, Eddy Performer RPM Magnum intake, TTI headers, carb tba.