[blykins]

The cam will be the biggest proponent for a flat torque curve. You want a tight lobe separation, as much as you can get away with without sacrificing the amount of vacuum that you need. Duration will need to be around mid 220's.

Otherwise your parts selection is ok. If you don't have the Blue Thunder parts, you may want to look another brand....BBM, Survival Motorsports, etc.

I use Racetec forged pistons in most my builds with Mahle 1.5/1.5/3mm rings. On a factory 428 crank, I use Scat rods.

I'd concentrate on a compression ratio of 9.5-10:1.