Roll Racing
Converter will help ofcourse but it's reletive: the higher stall the converter is, the less likely the car will be caught in the flat spot. 3500+ stall and you shouldn't get any dead spot. A 4000+ stall is like a M6 with 4.10 gears, every speed is a sweet spot.
Lastly, rollracing. A converter will help with shift extension which basically is where the rpms drop to after an upshift. This too is reletive to the stall speed: the higher the stall speed, the less drop in rpm's after shift. The more the motor stays in the high end of the power curve the higher the trap speed. 1/4 mile trap speed is usually what determines a roll race outcome. Hope this helps.

