you can drop your tank, but the best way to do it is to unbolt and lift the driver side of you bed. then its just a matter of bleeding your fuel pressure unhooking wires,and turning the lock ring that holds your sending unit in place.then just remove and replace in reverse order.
I have a 1978 Sierra 1500 and mine is near the secondary tank, passenger side of the truck.
The 2014 GMC Sierra-1500 runs on flex-fuel (FFV).
gmc 1500 sierra was fuel injected in '92
no outside fuel filter. inside fuel tank part of pump assy.
Fuel injection
The 2004 GMC Sierra-1500 runs on regular unleaded.
The 2001 GMC Sierra-1500 runs on regular unleaded.
The 2008 GMC Sierra-1500 runs on regular unleaded.
The 2002 GMC Sierra-1500 runs on regular unleaded.
The 2010 GMC Sierra-1500 runs on regular unleaded.
The 2006 GMC Sierra-1500 runs on regular unleaded.
The 2013 GMC Sierra-1500 runs on regular unleaded.