I have been wondering about that for a few days now about a lot of stuff...Name Brand Mech fuel pumps, Elect fuel pumps, fittings, fuel filters and the house brand looks the same..
It's kind of inevitable, AN fittings were pressed in to automotive use because they were high quality aerospace components. Outfits like Aeroquip started marketing direct to hotrodders and DIYers. Eventually anybody who could crank out a blue or red aluminum fitting with a 37° flare wanted in on the deal.
Speedway returns - no issues, send replacement part with a call tag. Summit returns - no issues, send replacement part with a call tag. Jegs return - I was pissed because the clutch i ordered came in dirty, as if a grease monkey tried to install it and gave up. I called them, they would not send a replacement until i returned the dirty one. I didnt have time to wait, nor did i want to shoulder the cost of the return. I dont want to knock them much, overall they have been good. But not quite as good as the others have been to me.
I buy from Summit 3 - 4 times a week and I always pad small orders with shop supplies to get the order over $100. so I don't have to pay shipping. I probably do 1 or 2 returns a month and I have never had a problem getting a refund.
I've had good luck with both big box suppliers and use Summit brand straight adapters. Leery of any non-named hose fittings but they are probably all made on the same line in China or elsewhere. Jegs has always been good on the phone with checking or finding something not listed...Summit always 2 days if the part is in Reno...
I would trust Earl's or Aeroquip, but any of the store branded stuff like Speedway, Jegs or Summit must be cheaper for a reason. In the short while I've been on the HAMB many guys refer to knock off parts as China stuff. We have all heard the stories about substandard "Vega" boxes that aren't Vega's, ****ty master cylinders, questionable suspension components from any number of sources and if you shop price then sometimes you fall into the old trap- You can pay me now, or you can pay me later. It is not always easy to select the right stuff now with so many sellers out there but generally price is the best indicator. If an Aeroquip -6 90* hose end is $17 and the same size fitting branded under the store name is $11 there has to be a difference other than the name on the package.