replacing full system on 172 - nut and bolt size

[montana]

my back box decide to fall off today so i am going to replace the full system from the cat back - i am anticipating the nuts and bolts being corroded , what bits do i need ?thanks

 

[montana]

right i understand that the center section to cat is M8 nut and bolt

center section to backbox - is this the normal U clamp with nuts on either side?

 

[Fred@BTM]

if its OE you'll need a sleeve clamp, about £20 for one

 

[montana]

yeah its OE, i will try my local factors tonight, thanks