Fuel pump recommendation & oil type
 

2003 Impala 3.4 base
It's got 275K on it and sounds a bit louder than it used to, still running great, so I'm thinking of going to Mobil 10-40 High Mileage from the current Mobil 5-30, both synthetic. Should be ok?
Also, any fuel pump recommendations? One ebay seller, oceanauto, is making it appear that he's got ACDelco pump assemblies for $65 but I'm sure they're fake. But what about the Dorman @ $88 or the Airtex @ $117.? Live near Atlanta by the way so doesn't get too cold.
Thanks!

I would only buy a real Delco or Delphi fuel pump.

Agreed but I'm wondering if there's a reliable alternative. Surely not everyone buys oem so if anyone has had a good experience with an aftermarket, I'd like to hear about it. Thank you.

With the work involved in replacing the fuel pump, it is not worth it to install a cheap off brand that might only last a few months or a year. I am not familiar with the Impala, but if you have to drop the tank, get a good reliable one.

Delphi is a good one, and as Oldchevy stated, you don't want to do this more than once.

That's no joke unless you have a hoist. No way I'd go cheap on a fuel pump, only to have it fail too soon.

As for the oil, its a tossup. At 275K I dont think 10-40 will damage anything, since its gonna have lots of wear on it.

Me, I just run full synthetic at the same weight. If its going to use lots of oil, I'd just find a newer Chevrolet.

It doesn't use any noticeable amount of oil and doesn't leak much. I just think it will help quiet the engine a bit. And it will then be the same oil as the other three cars. And I've decided on the ACDelco pump since this is the car that brings home the bacon. Thank you all for your input.