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

First thing I would do is recurve the ignition. Get as much initial timing at idle as you can without the starter lugging after heat soak. That initial timing plus whatever # to get you to 34* total mechanical. Low end throttle response will improve with more initial timing.

After you recurve ignition the AFR will change since you are igniting the air fuel mix earlier. If your going drag racing I would run a 600-650 DP. You need the pump shot to get out of the hole. You can tune a DP to get fuel mileage if you put the effort into it. Once it's dialed in you won't want to keep your foot off the go peddle.

Get a set of MT ET Street drag radials for the track. They hook good at around 15-16 PSI with a short burnout to clean them up. Street tires don't cut it at the track.

I ran a /6 converter in my 904 low gear set, TF2 shift kit, 3.91 gear and it was fun with a stock Magnum 360. Ran high 13s with street tires and lots of wheel spin.

Installed a 234@50 cam, drag radials and a 3200 10" Turbo Action converter. Car runs 12.30 and I'm still tuning. I spoke with Paul Forte at Turbo Action after sending him all my combo info and took his recommendation.

The $600 for the converter was the best bang for the buck performance wise I've spent. Drive it easy and you would never know it was a performance item. Hit the pedal and you better be paying attention.

You need to optimize your motor first and then get a converter and rear gear setup for how you want to use the car.