Replacement batteries seem to have smaller diameter posts on them than the OEM battery - at least SEARS batteries do. This makes the battery terminal clamps a potential 'lose' fit.
The battery terminal bolt can be fully cranked down and you may still have a loose fit - especially if the terminal/post has been cleaned many times or excessively.
They make a battery post product that fits over the post to enlarge it for a better fit to the OEM terminal clamp. I don't know how well they work/fit but it might be easier than replacing the terminal clamps. It also may just be another point for corrosion to enter a connection - unseen.
Dielectric grease is always good for a battery connection to keep corrosion to a minimum.
Member of the Dropped Valve Seat Club.
Replaced #4 Piston, Rings, Rod+Bearings, AERA Re-Manufactured Cylinder Head and a light Hone. Then CLEANED the hell out of everything.