You should be fine, but as a precaution, run the tank to 1/4 or below then fill, if you are mixing, I'd make sure you are adding a product like star tron to be safe incase water does form. If the fuel is going to be burned and used quickly, within 2 weeks or so it will not be much of an issue but if it may sit for a long time, like over a month or two with little usage, you may put the gas more at risk. I'd try and run it down to maybe 15 gal then fill the tank and add star tron or something similar, that will prevent some gunk and let any water that may form pass through as well. If you lose rpm's or the engine runs rough, you may need to change the filter, I'd highly recommend carrying a spare 10 micron filter, there is a chance it may get some gunk or residue in it after the first change, but once that is done you should be set. We switched over a few years ago like this and did not even need to change the filter everything went smooth, but we ran the tank down to about 15gal in a 92gal tank and put a liberal amount of star tron in for the first mix. Good luck!!