Arctic Cat gets their rivets from Fastenal I do not know the part # any more, but they are an extra strong rivet made soaly for snowobile chassis ask your fastenal dealer. They are steel and coated to prevent corroding. They use these rivets because they are strong. I am very sorry to tell you, but you are probably best off to drill them out and put the good rivets in or you have a great chance of failure. There is alot of stress on those rivets. It might not just fall apart the first time you ride, but after a while and some abuse from the hill you will probably see some distortiona nd the tunnel will get kind of loose leading to vibration while riding and possible track allignement issues.
