OK, first, be aware some years had a small tube welded on the timing cover.The reason is, at the factory, and dealers, a probe was uses to check the timing. These had 2 timing marks on the balancer. A thin groove one, for using a timing light, and one further away, much wider, for using the probe. So make sure to use the right one.
Now, if you suspect balancer has "spun", you need to put #1 or 6 on TDC. Most of you probably don't have a TDC finder, as it isn't used much so older mechanics, engine builders and small engine builders are about the only ones that would. Don't fret, you don't need to be precise. You do need another person. Use a wire down a plug hole, copper is safe, as you are inexperienced, I mostly used a thin long screw driver, over the years. You have to judge when the piston stops coming up. That actually is not TDC, as it needs to go a bit further, for the connecting rod to go "over center". If the timing marks are way off, it is bad. If off maybe a little- inch or so, you can get closer by going one way, when you think it has stopped coming up, stop and put a crayon mark on the balancer. Then go past(remove wire/tool), then do it again, going backwards, then put another crayon mark on the balancer, the middle of the 2 is close to actual TDC. If the timing marks are off, then it is bad. The repair, simply replace the balancer. BUT, while you have your fresh crayon marks, you can quickly set the timing with a light.
BTY, never had crayons in any shop, we used tire crayon markers,lol!
While down there, you also can rock the balancer back and forth, and see how much slop is in the chain/gears. Now it may seem like a lot, so judge it by the marks and the timing scale. Don't be surprised to see 10 to 20 degrees of slop, normal for these "old style" engines. 10 degrees will feel like a whole lot, so people easily get worried, for no reason. Once you get above/past 20, might be time to consider replacement.
A friend and a long breaker bar, and a socket extension can make these tests happen in just a few minutes.