Ya know, taking somebody elses word that your pretty new plane won't be flooded with gas doesn't really make much sense unless your friends come and get you to play baseball and then they use you for second base cause you don't have arms or legs.
Take the time to remove the cowl and measure how much bolt you have from the firewall forward..........then figure how thick your fire wall is with the blind nut installed...........then remove the bolt and measure the full length with whatever washers and stuff you are using..........now with a little subtraction you can convince yourself, or not, whether you have bolt protruding through the firewall in the proximity of the tank. Now if you do; cut it off so the bolt is flush with the back of the firewall when you have it tight. I know, you'll have to reapply your locktite but how do you expect locktite to stay in business if you don't use some........and some will say don't worry cause the tank is narrower than the bolt pattern for your mount.........well if it is, it aint much. Its your call...you can fix it yourself so you know its right or you can go play second base with your friends.