Well I don't have mine currently installed as the engine is out of the car still, however the welds do look quality The headers should be a nice addition to your setup but be sure to use locking header bolts as you'll be pretty upset with yourself if you have to change them out at a later time.
Slip fit. Just hope that you wont need to take the x-pipe off because once its on, it’s a pain to get off. When installing my torque converter I ended up having to cut the connection.