Lots of good info. here!
My '70 Challenger was set up with the Holley blue pump ABOVE the fuel cell, on its side in the trunk. The previous owner built it this way, I've had the car 20 years, and the pump finally needed a new check valve this year. Do I recommend this? NO! but it has worked fine for a long time. If I was starting from scratch I'd try to lower the pump, but if it aint broken.....

Back in the late '70s a friend put a delco pump in the engine compartment of his Barracuda, worked fine 'till it heated up and then car would starve for fuel, DON'T put it there!
Find a spot as close to the tank as you can.