Ok so I have a base (I think anyway) 1987 Camaro with the 2.8 V6 in it, 5 speed manual. It's got the weirdest battery drain I've ever seen. It will spontaneously "fix" itself, usually after I accelerate hard, and then after about three days goes right back to draining the battery. I KNOW the battery's good because I pulled it out of another Camaro that was just fine so I'm at a loss. Any ideas what might be the cause? I'm sure it's a short somewhere but where to look? Any common places? Voltage regulator maybe?

The alternator seems to be fine. Runs okay when battery's dead totally, though it does idle like a roller coaster when that happens.

If it were my car, I'd try another alternator. It's a likely candidate and they are cheap at most junkyards.