If it turns out to be a new defective new pump, why bother to replace the old working pump that is already on there? I would leave the old pump alone untill it starts to have a problem.
I have bought parts at Autozone before, I never had a problem with them yet.A few weeks ago I replaced the fuel pump on my 1983 Dodge van with one I bought at Autozone.
By the way, last January the NAPA store wouldn't let me use their restroom.Needless to say, I will never go to any NAPA store ever again. cuhulin