I should do some measuring before I comment, but I never had to cut my tank down on my Kitfox 4 rebuild. I made a box that went back in the firewall and mounted the tank there. It is kind of tight, but you can get the top off for oil changes. I used a couple of aluminum angels cut on one side to match the tank curve and the fasten to the back of the box. Two heavy duty hose clamps hold the tank to the aluminum angels. Of course with mine, I don't use the tank brackets that come from Kitfox for the motor mount. JImChuk