E-street vs Promaxx vs 440 Source

Exactly.
The Stealth Head is it’s own casting, although the basic port configuration is very similar to the others(i.e. another copy of the RPM heads).
Compared to the other import castings, I actually prefer the port openings of the Stealths on both intake and exhaust.
It’s not a big thing either way......but they aren’t the same.
page 9 - and we are finally getting some details on differences between the heads, ports and perhaps an opinion on what may be a preference. :)