383 build for efficiency

Maximum lo speed torque or most efficient
it's not maximum torque..that would be well beyond the point of diminishing returns.
like paddling a canoe..there is a point where you get the most speed with the least amount of work.
and if you paddle twice as hard you will not double your speed,but you will go some measure faster.
Everything mechanical has a sweet spot where you get the most bang for your buck.