These sound like a great idea and a nice improvement! Biggest question I have, and it may help others, is will this work in an E body Rallye Dash as well? Thanks for making these!
Thanks for the great question, JD. Unfortunately I can't give a 100% positive answer, because I've never had the luxury of owning an E body (not sure which emoji to use here, too much upfront investment for my means, lol).
What I can say for sure is that these are pretty easily adaptable to any application that requires ~5Vdc to feed the gauges. If you wanted to replace the "plug-in style" IVR that the A body standard clusters use, you certainly could. My simple design only needs a 12Vdc input and a ground, and it outputs a rock-steady 5Vdc. The only variation from a rallye cluster installation would be how you get those signals into the IVR and then out of it to the gauges. In the example of the A body standard cluster, that would amount to using blade connectors to interface with where the old plug-in style plugged in, instead of the ring terminals you'd use to connect the IVR to the rallye gauge terminal posts. It would actually be a simpler installation, because you would not have to mess with modifying the rallye fuel gauge.
My best guess is that Mopar still had reduced voltage-fed gauges in the E bodies, so I would be shocked if mine would not work. Maybe someone else on FABO has that knowledge and can confirm or deny.