RE: Upgrading the fuel tank on std Revo
The link he has posted is intended to be for when you have removed the opti-drive and gone FOC, even though they state that you don't have to, it is highly recommended. I have no idea where you would put the opti-drive with that in place.
I have seen a couple of pics on various forums of guys who have put other thanks in the standard position. I have no idea what tanks they were or what they had to change to enable them to do that, unfortunately.