How's he going to remove the sending unit with fuel in it and not get doused in gas?Yes 5 gallon plastic buckets will be fine.
Why drain the fuel?
I second this idea. I've got a 6 gallon gas can I use to transfer fuel into for just this sort of task. With the little hand pump, I can suck all the fuel out of the tank so that all that drips from the sender is what little is in the line between the tank and the pump, mabe half a coffee cup worth. No mess. Very little fume. When done its easy to put fuel back in the tank.Why get so complicated??
You can get a cheap gas pump (has a hand-operated pump on the side) at most auto stores, Northern Tool, even Amazon.com. I use one all the time to transfer diesel from barrels into my truck. Those pumps are less than $20. Park another car right beside the Mustang and just transfer the fuel from the Mustang to another car. Easy and safe.