If you look in the rod big end bore, you will see that one side has a wider chamfer than the other. That side faces away from the other rod on the crank pin. It is there to make room for the radius between the crankshaft web and crank pin. If you install the rod facing the wrong direction, it will lock up your enigne. A hard to turn engine is normal. I had to ues a big screwdriver or prybar in my flexplate to roll my engine over during assembly. 7,000 miles later it is still tight but sure runs great.