https://www.enginelabs.com/engine-t...-the-most-out-of-the-street-demon-carburetor/
Some good info, if you haven't found it already.
With the tunnel ram, your accel pump may need to be unreasonably huge. Plus there's some setup involved with the timing and stroke of the pump (detailed in the link).
If you're still having the low rpm part throttle stumbles, then maybe the step up springs need some attention (or the metering rods).
Will be curious to see what the solution is once you work it out, a tunnel ram is one of my "bucket list" items as well, but likely with efi.