Looking for advice on a blueprint engine.

Horse apiece, keep in mind the difference in torque curves. With a heavy truck, the flatter the torque curve is better. Less piston pin height, the lighter the piston and quicker it will rev. If it was me, I’d balance the crank by shaving it as opposed to drilling holes to balance it.

Then again keep in mind that a 1/8 inch overbore is the same horsepower gain as an inch of increased stroke.

As for the length of the rod, longer it is to a point, the less loading on the thrust side of the bore.