1971 340 right torque convert

If you have the original transmission and converter from the 71 340, get the factory 340 converter rebuilt. They're a very good converter. If my failing old memory serves me right, the converter in the new Duster to your right stalled somewhere between 2300 and 2400 rpm, providing the brakes could hold the car from moving. However, if it's not the original 340 converter then the 2400 stall converter you're thinking of buying will be an excellent choice. For a stock 340, as good as they are, you probably won't be happy with anything higher in stall. Your choice on whose make though. Some will like your choice, others won't. I'll remain neutral, as I've seen enough converters apart to know that any converter company can have issues.