Swap A833 for Auto - 71 Duster 340

I'm assuming that is a joke :)

340s like gears, or higher stalls. With 3.91s they can scare the crap outta you.
But I've always had 4-speeds and always had 3.55s or better. And with 3.55s, I always had to rev 'em up and dump the clutch to get the tires spinning. All of mine were stock-cam,hi-compression models. My nearly new 1970 Swinger340 liked 4.10s to pull the G60-14s. That was a great city-car.