I had a customer in SO CA high desert (4000+ Ft.) that had bought a 1966 or 1967 clone Plymouth NASCAR of Marty Robbins old race car that had one of those intakes on it that I worked on, it had extensive mods in the intake from Petty Ent. I think.
I rebuilt it with a 4 250 stroke crank assembly set up for pump gas back in 2000 or so, I dyno that motor and it had the best EGT readings I have ever seen on any carbureted Mopar motor It would level off above 900 RPM to have within 50 degrees F on all 8 EGT and hold that from light part throttle to WOT up to 7500 RPM
I didn't think to take pictures or draw a picture of those mods, DANG IT