@ Lon and Will, thanks for the awesome info! I know know that 274B and 5U4G are somewhat similar and can be interchanged with caution.
@ Will, yes on the 2 RCA's that I have one of them is marked as 5U4G, the other tube has no markings, but looks exactly the same so I'm thinking it rubbed off or something.
Interestingly, I have 2 other tubes where the box says Tube Store Preferred Series and the tubes are stamped "tubestore.com 274B preferred series" with no other markings, but after checking the
tubestore website they are listed as 274B/5U4G and seem be from China/Shuguang.
I have most the info on these:
Tube = 274B/5U4G
Amp = any amps Steve indicates a 5U4 or 5Y3.
Brand = Shuguang
Years = seem to be current
Country of origin = China
Position = Rectifier
Price = 31.95
but has anybody heard them and what were your impressions?