The Gnarly and Fatty of that year are the same design pipe made of different gauge steel. The OEM GG pipe is heavy like the Gnarly and a great pipe IMO.
Thanks. Good to know. It sure works great on everything I've ridden so far.
When I get the new gnarly I'll send the oem pipe and two fatties out for dent removal.
I would give FMF a call. When I bought my 05 it came with a Gnarly (05 vintage) and a fatty (09 vintage). The 05 gnarly was all low end and did not rev much at all. Real flat upper mid and top. The fatty was pretty good all over and reved much better. I put a spacer in the fatty and it helped the midrange and it still reved well. I read that the gnarly changed so I purchased one in 11. This gnarly performs right between the old gnarly and newer fatty. This is my favorite of the three.