I stumbled upon this thread and had to put my .02¢ in. I own a bone stock 2006 Buick Rainier CXL V-8 w/awd. It has the cast iron 5.3 with aluminum heads. Probably makes around 300 hp on a cool day. It's not "quick" but I figure anthing with a small block Chevy and all wheel drive must be at least "capable". It leaves a redlight pretty hard. The awd works well and has for two years now. I don't beat the crap out of it but I won't pass up the chance to pick on anything at a redlight. At 150k miles it runs smooth and quiet. It might blow up tomorrow but I'd recommend this vehicle to anyone wanting a "sleeper". This thing looks about as threatening as a Tugboat til the light changes and it chirps all fout tires and disappears.
Like I said, it isn't "quick" but it's certaily surprising from 0-100.
You could buy one of these for cheap and add boost. You could get a good summer of play out of the stock engine before you killed it at 9lbs of boost or less.
So there ya go. Pick up one of these for $4k, add $1500.00 for a cheap turbo kit, about another $3500.00 on misc stuff like four drag radials, a tune, and maybe upgrade the fuel pump and injectors, and you'd have a serious saturday night special. Hell, gut the thing out and get the weight down and you'd have a monster on your hands. Well...until the drivetrain goes off like a big grenade but you didn't ask about longevity. I've been driving it for two years and it's not dead yet so it really must be fairly tough.