Street Demon tuning experience

I've been running the 750 Street Demon on the 450-hp 360 in my '70 Duster for about 5 years now. One thing I've learned about tuning it with a WBO2 sensor is that the instructions aren't lying when they say to target 13.5:1 AFR for cruise. That does seem on the rich side but I've tried to go leaner and it just throws off the rest of the tune; it'll stumble and just not accelerate as easily when not in the power enrichment mode. I've confirmed from checking my plugs multiple times that the tune is in fact spot-on. Gas mileage also won't improve going leaner because you'll be using more throttle.

I'm not sure why it shows up rich with a wideband but I don't worry much because the gas mileage is as good as it could be considering the loose 2800 RPM stall converter and 3.55 gears. It also performs very well, this past weekend I made my first 1/4-mile pass with the current engine and drivetrain and it ran 12.65 second ET at 108.15 MPH and I feel like I let off a touch early as the drag strip had a very short shut-down area which freaked me out once I realized it already going over 100 mph lol.

My only complaints about the carb are the difficulty in changing jets as you mentioned, and the fact that it has trouble keeping up with the fuel demands of this engine above about 4000 RPM. I think the bowls start to run low up there and my basically stock fuel system can't keep up. These carbs (like Carters/Edelbrocks) are very sensitive to float bowl level. Increasing secondary jet size doesn't have much effect at higher RPMs for my combo.

How much have you messed with the metering rods, and what size are in it now? The selection is pretty wide for those. I tune with the metering rods as much as possible until I get to a max or min size then I swap primary jets, in general.