[Wayne 962]

I don't use the factory ones, I just use standard copper ones that are oblong (so they are self-locking). The factory used nuts that were 12mm on the outside so that they would be easier to get on and off in tight spaces. Frankly, with the right tools, they are easy to reach regardless (just use a swivel socket, like the one pictured in my book). Piece of cake.

So, in conclusion, I would use the six barrel nuts and six of the copper self-locking exhaust nuts. I hope this helps answer your question...

-Wayne