Question on changing SB mechanical fuel pump

I'm about to replace the stock mechanical fuel pump on my 1967 Barracuda, last replaced in 1978. Dumb question...

So, the fuel tank is full. When I cut the rubber fuel line feeding the pump, are the fuel tank contents going run out on the floor or is the pump mounted higher than the max fluid level in the tank? Should I run the tank down below half-full before doing this job? Factory manual does not provide a procedure for changing the pump, would prefer NOT to wash garage floor with gasoline.