Belt too tight?

[Skunksmash]

I recently had to replace my main belt on my 87 5.7L TBi. The only one that isn't a v-belt. It has the little ridges all across the underside and its about an inch wide. That belt. It was squealing horribly and was about to bite the dust.

So I replaced the belt, and the squealing stopped. But how do I know how tight to tension the belt? As I'm sure most of you know, you just use the alternator to tighten the belt. You just get your prybar in that hole in the alternator bracket, and pry on the side of the alternator while a buddy tightens the alternator bolt. Then presto, the belt has tension. But how much is too much? How far do you go? How can you even tell you're anywhere near the correct tension?

Same question for the V-belt that connects to the smog pump down below. You can change and adjust the tension on that belt just as you would with the main belt.