I bought some Raybestos rear drums for my 1990 Ford Ranger. The drums were so off balance that I put the old drums back on. With the new ones I drove it around the block and you would swear the wheels were out of balance. When I took them off i put them on my bubble balancer and they pinned the bubble to the side. Both were that way. I then put my old ones from Advance Auto on the bubble balancer. Both were dead center. Guess I didn't need those new ones after all.