My car runs and starts, but there is this somewhat loud clacking/clattering noise coming from the engine bay near the alternator.
I did have to replace a bolt and a belt due to the bolt being REALLY rusty and the belt being REALLY old (approx. 46 years old).
I tried looking it up, with someone saying it was my belts and belt tensioner or it being the oil, but my oil is fine.
I'm really hoping to have the resolved so I can get back to cruising around.
Please, help me.

 

This happening on your 1970 Impala? Did it start doing this all of a sudden? Metallic clacking noise to some other tone to it? To isolate thigs, if you take the belt off of it and start the engine momentarily, and see if it still makes the noise. This should isolate the noise to the belt, something driven by the belt or something not related to the belt.

 

This was after my parents and I went out of town to pick up some things.
I was about to go and air my tires up because my front one was low due to cracking, and I started my car up and I heard this awful ticking noise.
I should be able to try your suggestion out around 4:00 after work, hopefully this will fix it.

 

It may not fix it but at least isolate what's doing it.

 

So, I never got around to taking the belts off, due to my family moving, but I flushed the oil out of my engine and replaced the oil filter, air filter, and oil and it kind of toned down the clanking noise? It's still there, but it's much quieter? Should I try taking the belts off still just to see if they could be causing it?