I can only speak to the 7.3 gallon Talon tank - I removed that tube and gained 1.3 gallons which gives me 8.6 gallons. I know this because I ran it out of gas on the trailer after syphoning off most of the fuel in the tank, then filled with 8.612 at the station. I did gain a little fuel smell but it had to be extremely rough and downhill for that to happen. I extended my tank vent up under the radiator and haven't smelled fuel since (still worth the extra capacity unless you have a wife, kid(s), or dogs, IMO).