Howdo. There's a lot you can do to the gm v6, it's a good torquey engine. First off it will love a decent cold air induction kit as it can struggle to get enough air in at high revs due to all this emissions control rubbish. A lot of people put the cams from the 3.0 v6 in to get up to around 190 bhp once cammed and remapped.
I've had 3 gm v6 cars and always liked the engine, makes a good sound and feels solid.
Forgot to say we've had a few threads on here about the gm v6 so have a search and you should find some good stuff.