Thought I would add my own experience with an Airtex pump, though my vehicle is a Dodge Caravan, not a Chevy Blazer.
About a week ago I had to change out the fuel pump (original) after 120k miles; pump still worked fine, but had developed a small crack in the out-going port that had a nasty habit of spraying fuel towards the exhaust pipe. Anyway, I got a replacement Airtex pump from O'reilly, and put it in with a new fuel filter. The new pump had a bad check valve out of the box and wouldn't hold pressure when the car was shut off... of course having just replaced it I tore the rest of the engine apart to check the fuel rail and injectors before coming to that realization. Unfortunately I've just put another Airtex in the tank I got from the warranty... this one works so far; does run about 2 PSI higher than it should, but at least the check valve is working for the moment. I just wonder how long it will be before this one dies. I wonder if O'reilly will refund the cost of this piece of junk so I can buy an OEM (90 bucks more and not typically in stock)