2.5" intake and 3" out the back but with stock manifolds. I've always ran the .54 AR turbos but started out with JDM downpipes and smaller intake and exhaust. Every breather mod made a noticeable seat of the pants improvement. It seems to me to be a good street combo but I have nothing to compare it to and haven't had it on a dyno.
Will be switching to .63 AR in the next couple of months along with bigger exhaust manifolds and I'm anxious to see what kind of improvement it makes.