Here's a pic of my 2000 XR4 with 440 kit and Mikuni pumper.
I have run the IMS 4 gal tank on it full time for the last several years. Takes a little while to adjust to the handling and weight but I don't notice it now. I love being able to go all day at places like Taylor Park without having fuel issues.
When I had my suspension done professionally, I had them take into account the big tank.