Looking at getting a v6 3.8 to keep insurance down. Planning on doing shorty headers, 6" magnaflow racing muffler dumped.

1. How long does it take / what is involved on installing shorty headers? I installed them on my Silverado and was pretty easy, but there is more space in a truck vs a camaro.

2. What diamater pipes are best for proper flowing / scavenging / sound.

3. Should the Y-pipe be replaced with a less restrictive one or is the stock Y-pipe good to go?

I live in CA smog = issue

 

You can go to shorty headers, but unless you are planning to rev the hell out of the engine, you are not going to see a noticeable difference in performance compared to the factory manifolds.