My 3600lb 64 Savoy has a B1 original headed 540. It has been 5.60's back east. 5.70's here in Vegas, it also has a 4150 carb on it, so yeah you are leaving plenty on the table and with a glide if the converter is tight and the drop back is high its gonna be slow. You need to be much closer to 64-6600 if not more with a lite car and a glide.

Yes pulling the chip and wooding it on the brake will tell you as well. Most Super Gas guys leave off the converter, but drop back will tell you the stall speed.