I have a new stock fuel pump from Onan and one of the aftermarket ones. I can say the Onan pump, for it's size, is noticeably heavier than the aftermarket ones. I find that interesting and noteworthy. I don't know what that truly means, but my guess is better materials in the Onan one. BTW - it took 4 months to get the Onan one, as EVERYONE was out of stock. PPL, RV warehouse, and so on. I'll be changing mine out with the new Onan one next weekend.
Al
Just a thought - maybe I should hook up each one and see which one shoots out gas the farthest?? Thoughts anyone???