Have been waiting patiently for someone to build an oversize tank for the '06 450 for longer rides. Bought one from ZipTy Racing the other day, a 3 gal IMS which mounted up perfectly and is only minimally wider than stock at the shrouds. The groove under the saddle needs to be lengthened approx 1/2 inch to make the seat ride far enough past the post on top of the tank. That was the only custom work needed, i just used a dremel. The front of the tank mounts securely to the frame using the oem mount unlike some other IMS tanks. OEM mounts, petcock and fuel lines are used as well, making it a 20 minute switch max.