Flange size?

Well I just got some AS&M headers from a person on the board and was wondering what the flange size was for the collectors that bolt onto the y-pipe. Any help or some sort of direction would be great for I could get these suckers in my car asap.

I have the RK sports which are basicly the same headers.

2.5" between headers and Y
3" between Y and cat


I had to jack up the motor a bit to get the passenger side in

What do you think of the RK Sports? I am talking with a guy about buying a used set from him. Pros/Cons? Sorry to highjack the tread just wanted to make sure I am not making a mistake on my purchase.