to rebuild or just lower end 71 440

I think for peace of mind I'd stick rings in it too. That way I know the same clown that messed up the lower end didn't mess up the top end. Scores in the bearings mean dirt in the new ioling system, and probably dirt in the cylinder walls beating up the rings. Now's the time to do that. But aside from rings, it's probably fine. Repairing the lower end is a viable process. Also - if you didn't measure the old crank and bearings to make sure they were the cause of it, you may want to measure the lifter bores to and make sure there's not a problem with wear there causing low oil pressure.