Frankendart Lives!
For anyone interested, I hooked into the stock O2 sensors with a multimeter (they just put out a 0-1v signal, so it's pretty easy to read), and found that the car was pretty lean on full throttle. I know it's just a narrowband stock sensor and not super accurate, but I went ahead and bought a bigger set of jets for the secondaries and the car is a whole new animal. It pulls hard all the way up to 6000 and my little windshield accelerometer tells me the jet change alone was worth 20-40 hp. Still stumbling off of a full throttle hit though, was going to try to put a bigger discharge nozzle on it, but need to order one as no one around here stocks Carter (Edelbrock) carb tuning parts. That or I need to find someone around here that would let me borrow a different carb for a day and see if that fixes it.