Again, your work and car are fantastic.
I'm prefacing with that so as to not have this misconstrued. I like the lower profile of that design (and almost all manufacturers use that basic design) electronic cutouts, but I really believe the Doug's design is better. The advantages for the Doug's design I perceive and have experienced are: The opening is completely unobstructed which means better flow, and better longevity than the "butterfly" assembly. The ones like yours are always exposed to very high temperature exhaust gasses. The "guillotine" design completely moves the blocking plate out of the way.
It's also "self cleaning" in that as the plate slides, if there is any carbon buildup, it is scraped away and blown out of the system.
I've had my Doug's for at least 5 years. The only problem was replacing a motor, that had a serial number in a recall, and they sent 2 replacement electric motors of which I only used the one I needed and kept the spare, all paid for by the manufacturer.
I'd appreciate your input and that of others, but I don't want to sidetrack your build thread.
Doug's 3" cutouts, just like mine:
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