Choosing the right stroke for a 340

There are many ways to skin a cat. A over square motor or overboard motor almost always will be a more efficient per cubic inch/more horsepower for the cubic inch the reason one reason being angles of rod and crankshaft begin to sideload cylinders as the stroke goes up if the rod length remains the same. Also piston speeds increase dramatically as stroke increases requiring premium parts to achieve the same RPM. Stroked motors develop more torque which is desirable and relatively easy to achieve. Horsepower is more a product of the head and induction system for the most part. Going to a 4 inch crank is the easiest way to make more overall power from a 340 but definitely not the only way.