I'd still love to know if there are differences between the different ones marketed.
They could all be from the same casting foundry...or they could be different.
Hard to tell with all the fly by night MFG that goes on in China.
I'd like to know if any of the offerings are better than others.
Especially since there's such a wide range in experiences from "they suck" to "they're great".
I've tried them from 2 different suppliers, SpeedMaster (Black Friday specials) and DeepMotor (about a buck and a half at the time, slightly more now) and they were identical. Even the same bag of hardware included.
Currently running one on my 5.9 Mag powered '88 Dakota with a stock bottom end, 600 Holley, and a warm .480 lift cam. No ETs, but she defends her honor quite admirably.