I've got the KB hypereutectic's with cast Hastings rings in my 340. This has been some great info. My motor is still on the stand. It's a .040" block with steel crank and eagle I beam rods. Had the rotating assembly balanced, and topped it off with X heads. The cam I'm going to run is the MP 484/284 with the stock iron intake and a reworked BB Thermoquad. Looks like a need to be really careful tuning this thing.