If you need help deciding about spending $3.678924 and $4.9876 there's more to that than meets the eye . Buy the pump and if it doesn't work right send it back . WTF
Its not about saving money on the pump, its about avoiding Rockauto's multiple warehouse shipping BS.
To OP: Have you plugged the part # for the pump you want into Amazon? I've started looking up the parts I want on Rockauto's website, and then putting brand and part # into Amazon's search bar... I often find what I'm looking for for the same or slightly less money than Rockauto, and Amazon Prime usually gives me free shipping.
Oh yeah, I've installed hundreds of Airtex pumps, and generally had good luck with them. They are certainly better than GM's factory stuff.