In the next few days im going to be upgrading my exhaust (axleback) and i wanna know what size gasket and bolts i need because it doesnt come with any hardware and i wanna get them before hand so when the exhaust comes in ill be all ready. Also should i just go to a nissan dealership and get the parts from there? Thanks!

 

depends on what size axle back your getting

 

Axle-back will bolt on with existing hardware so you don't need anything.

 

I was figuring that, but isnt good to change them. They seen 12k miles already.

 

I didnt change my hardware after ~30k miles. Axleback too

 

OEM gaskets are layered metal while the ones I got with my Ark were more like cardboard with foil but I don't think that gaskets are a wear/tear item so I wouldn't be worried about changing them.
I'm not sure about the rear gaskets but the ones on the cat (different size than the other two sets) were about $16/side at the local Infiniti dealer. I'm not sure if a Nissan dealer would carry the same.