Finetuning questions - do I need a high-stall torque converter ?

Ideally you want your stall speed at within 500 RPM of where you make peak torque.

If you are questioning the carb tune, and the convertor stall I would have it chassis dyno'd and tuned.

But you said you had it dyno'd and had it AFR tuned. So the carb shouldn't be the issue at least not in regards to the tune.

Where did it make peak torque?

Seems like you have a relatively small cam. Fairly docile.

Carb is small and I'm not a huge fan of the eddy carbs in regards to performance. They are great for a guy who can't tune a carb and just wants a bolt on, turn key and go carb. A 600 hp style Holley would suit you much better IMO.

310hp doesn't tell me much. My car makes 2314 on a chassis dyno. It runs 11's in the quarter. Again, I'd like to know where it made peak torque. Doesn't matter how much it made.

You have no tire under the thing. It should boil then off the car. The gears aren't helping you though.

IMHO you'd be better off going to a higher stall speed custom convertor. It's going to be a better converter all around.