I have a 99 WR400 and am looking into getting a narrow tank for a slimmer feel that would hopefully allow me to transition my wieght front and back easier on the seat. I know that the WR450's have a smaller and narrower tank so I would like to ask those whose who have ridden both the 400 & 450 bikes if it makes a lot of difference. I would also like to know that if it is worth the extra expense what you would recommend as far as brand of tank. I know I could replace mine with a YZF tank and seat but I would like to maintain at least a 3 gallon tank unless the smaller 2 gallon +or- tank of the YZ does not seem like a problem to most of you. It would be nice to have a larger & narrower tank that fit my stock seat since this would be cheaper then having to replace the seat as well. Whatever light you can shed on this would be greatly appreciated along with any manufacturer or web site info that you could direct me to if you feel this change is worth it.