Is there something common on a 95 FWB that would make it idle rough. The car runs out really smooth, but when sitting it is a little rough. I am considering this car for purchase, but I didn't want to inherit a major problem like burnt valves or something like that.

Just wondering if there was some common, inexpensive fix possible based on someone's experience.

Opti-spark.

Is it something you can disasemble and correct the problem like a rebuild or do you have to just replace it with a new one?

Someone with more LT1 experience should chime in here but it sounds like opti-spark to me. It is a very common failure on the LT1 engines. It must be completely replaced and most people do the water pump at the same time because it takes a fair amount of tear down to get to.

Beware PCM codes as well to verfiy an Opti Spark issue