After you press the cases together. Support the cases on two 4"X4" blocks and gently seat the bearing's in the case. You should be able to look down at the crank through the cases and see which side is binding? I usually thread the nuts on each end of the crank. Then use a plastic dead blow hammer and firmly tap the end of the crank. Be careful not to damage the shaft ends, also you can damage the new crank bearing's if you beat on it hard! Do a few blows, then check to see if you have freed up the spinning assembly. If it still tight, flip it over and do the same thing to the other side. The cases must be supported! Note: you should have all the case bolts in and torqued.