Fuel in engine oil

After replacing the fuel pump I would not attach to the line from the tank. I would use a 5 gallon gas can and attach using a length of fuel line directly to the input of fuel pump and then start the motor. Run it for 10-15 minutes and allow it to reach operating temperature. Watch oil pressure and temperature gauges. Be sure there is adequate ventilation!! Old gas or gas left in a tank for along time even with fuel perservative may give off a smell in the oil. Good luck