One more Gonkulator comparison I ran this by accident!
With the ?stock? 1600 stall, the 390 Holley gave
2.33
15.48 at 85.8
6.99

The 600 Holley actually Gonkulates SLOWER with the 1600 converter as it loses off the line:
2.36
15.51 at 86.0
7.03
So if you stay stock converter the little carb is definitely the way to go. Of course, as I found in the carb shootout, sometimes an engine will just "like" a carb better than another one, regardless of size. Just have to try em.