Even new ones have a high failure rate and the brand doesn't seem to matter. Just because it's new or newly rebuilt doesn't mean it'll stay new. The last new pump I bought lasted me maybe 5,000 miles or about a year before it started leaking oil and making a mess. I replaced it's predecessor because it put out almost 8 PSI and invariably flooded the carbs when shut off, even for a minute. I have been using an electric pump that puts out ~4psi since. Six months and a dozen 350-mile trips over the mountains; so far so good. They must be filtered on the inlet FWIW. I know it doesn't look stock but if you're still working these ol' trucks you have to make a few work-arounds.

1951 3800 1-ton
"Earning its keep from the get-go"
In the DITY Gallery
1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.