Previous owner said it was a stage 4 so I'm taking his word for it. I don't know much about all the stages but I'll post as many pictures as possible.
The inlet looks like it had a port job done too.
As for the pulley I think it's a 2.6 believe it or not. I measured the circumference and divided that by pi and am getting near 2.6 (think that's how you do it?).
Price is $600 shipped.