what did you guys use to connect it? bolt with a spring and nut or just bolt and nut. this is for a 2.5'' 2 bolt flange. where can i purchase the spring set up if needed. or what do you recommend. thankz

p.s i will also have a flex pipe on the downpipe

 

you should be able to buy the springs from the dealer...you do use the springs or else you'll end up having an exhaust leak...