none...I've run it down to 1/8 tank...no issues. It's the same exact setup all the 4th gen LS Fbodys used (except the emission part). Someone here explained how the check ball in the fuel bucket works. The very instant the pump senses it's sucking air (cause you are low on fuel..turning...etc), the check ball stops the pump from pulling from the tank..and directs it to draw fuel from the bucket. Now fuel is always in the bucket...because the return line is always returning fuel to it. It's a great setup for people who do not have wild HP setups. Stock fuel tanks...to my knowledge ...do not have baffles. The "bucket" is the trick. The fuel in the bucket also cools and lubricates the pump. This setup works well, it's quiet, and is not terribly expensive. I'd like to have a "Rick's stainless steel" tank...but I didnt not want to pay what they are asking for it (?$1000?). I do get a gas smell while my car is parked in my garage. I am going to connect the fuel vent line from the 4th gen pump bucket to a charcoal filter from a motorcycle (ebay-Harley Davidson). I've read it takes care of the smell....otherwise I am out $10 and will continue to leave my garage door "cracked" to let the fumes escape.