I would think a stroked 340 with an xe268 cam would seem small and pump out the torque all the way through the RPMs. Had to do a lot of tuning to get my 318 to run right with that cam with a stock converter.
I think it's got more to do with amount of overlap per cid (cid & head flow ratio probably plays a large roll too ) cause the low band of rpms the engine doesn't like to operate in than low rpm torque output.