I think after a year of trying everything on my Nova to cure the rev problem, I think I FINALLY found the smoking gun. I took the carburetor apart again to calibrate it using the Edelbrock calibration kit. I removed both of the needles and seats and found that the last chance screen behind the seat on the drivers side bowl was plugged with crud. I also cleaned out the passage with Berryman's chemtool and blew it out with air and a whole bunch more crud came out. Put it all back together with larger jets and rods and it seems fixed. It now pulls hard all through 1st, 2nd, and 3rd. Thanks for everyones advice.

Jeff