In addition to the crank main bearings, while you have the engine open it would be a good idea to check the transmission mainshaft bearing that is pressed into the case. Roll it with your fingers, if there is any resistence or rough spots, replace it. Also grab the inner race and try to move it up and down, if there is enough radial play that it can be felt, replace it. Also do the same with the transmission countershaft bearing that is pressed into a carrier plate that mounts to the left side of the engine.
If you do have to replace one of these, make sure to ask specifically for non-sealed bearings, otherwise they will try to give you a sealed bearing. I hate having to go back because I got the wrong part.