Assuming they're looking at a list of torque converters used with 240 AW70/71 (non 'L' designation), the higher stall speed converter is most likely the one used with the turbo cars - because of the astonishingly gutless nature of a B21FT below about 2500RPM resulting from the turbo lag of the big Garrett, a higher stall speed was spec'd so the engine would reach higher RPMs sooner and get the turbo spinning faster, before being loaded up. Practical upshot - I'd use the lower stall speed converter with a B230F unless you particularly enjoy trying to humiliate rice rockets off the line.
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Chris, Dartmouth NS Canada 70 M-B 280SE, 83 245DL, 84 244 turbo, 90 780 turbo, 92 VW Golf, 90 740 Rex/Regina

High or low stall torque converters provide opposite benefits and shortcomings. I'll try to answer generically -- but I'm prefacing that by suggesting that you really should try to match the stall speed specs for your car's AW-70, as no one knows your Volvo engine's needs better than the Volvo engineers that designed it.

However, we have to allow that they're compromising their design to accommodate typical (or average) drivers' needs. So, assuming that you've got some *special* purpose in mind, here's some advice.

If you have a high stall speed (i.e., rpm) converter, this generally means that you've got more slippage -- this allows you to pull away from a stop at a higher rpm that is closer to the peak torque band of the engine. In other words, faster off the line -- it may feel like (but isn't really) you've got additional torque multiplication or a lower first gear (again, not really). Do you race your Volvo (I say with a smile)? You would want this.

If you have a low stall speed, there is less splippage. When would you want this? Off-roaders prefer this when they're using "engine braking" to hold down their speed (while not using their brakes) while descending steep hills. I can't really think of a good reason for this in a Volvo. Maybe (and I'm only speculating wildly here) it might slightly improve highway mileage (driving at at a constant speed in high gear), like something the AW70L (lock-up torque converter) does much, much better (but isn't available for 240's).

If you're an ordinary owner, even an enthusiastic driver as well, I'd ask for the stall speeds of these T.C.s and then see what the standard Volvo T.C.'s stall speed is, and match it as close as you can.

Good luck.

Stall refers to the non-linear coupling between the input and output or stator and rotor turbines. There is a speed below which very little torque is coupled from input to output. This speed depends on the design of the turbines. High stall allows the engine to rev higher before being loaded or coupled to the drive train. Hence, the engine is higher up it's horse power curve. This is a common practice in drag racing. This gives better acceleration at the expence of milage and wear. A lower stall speed gives a quiter and more economical ride. The stall speed in RPM is probably not very different in street car transmissions and represents fine tuning by the manufacturer for each model. You should be able to get the stall spec for your model and what models used the other speeds from the shop manuals.