But since your springs are of different vintage, it probably wouldn’t work. I only mention this if you end up resorting to replacing the other spring.
Before going that route, try this. First, make a note on which side of the door is higher when closed. On the side that is, try loosening it by ¼ turn. Then, check for level when closed. Repeat until both sides are level. If you go too far, tighten 1/8 turn until level. Then, check to see if the garage operates properly. If not, the garage door will most likely be heavy and hard to open, so tighten both sides in ¼ turn increments until it feels the way you want it. Always tighten both sides, not just one.
If you end up again with one side higher than the other, then you will need to start the process over, and it may take a couple of times. If it does not work out, you may want to just replace the other spring.
Bear in mind, though, that these torsion springs are VEEY DANGEROUS. One slip, and you could loose a finger, an eye, or your life.