Stock 340 Dart on dyno

some builds go long duration cam,big port heads,big carb etc which make an impressive hp number (at high rpm) but idle quality and lo rpm power can be disappointing without a gear and a converter.

I concur
The way I see it if you ain't gonna gear it don't build especially with small displacement. You either got to build torque in the engine ( displacement) or in the gearing. Most run 3.23:1-3.55:1 that's what they should design their engine around that's why 408 are so popular.