Back to the original question- - - -your 350's best torque range is going to be determined by the camshaft profile and the compression ratio of the engine. A "torquer" engine is going to have fairly short time when the valves are open on each cylinder (called "duration") and a moderately high "lift", the amount of distance the valve moves from its closed position on the cylinder head, and its fully open position that allows the gases to move in and out of the cylinder. Cams with a duration of 270 degrees of crankshaft rotation or less on the intake and exhaust valves will have a smooth idle, plenty of low sped and midrange torque and good all-around performance at variety of engine speeds. As the duration and lift increases, the power band shifts toward higher speeds and low and medium speed power diminishes. The two biggest mistakes rookie engine builders make is "Too much cam" and "Too much carburetor". Doing race engine stuff on a street engine is an exercise in futility, no matter how the hotrodders protest that "It runs great"- - - - -compared to what? For a long time, Chevy dealers offered a new buyer a free STD- - - -so they could have something that "runs"!
Jerry
