The lockup converters on AOD's are weaker than later AOD-E and 4R70W versions. However, it should be sufficient if it's just a cruiser, even if towing a reasonable load. To protect the lockup, you can feather the gas when it's locking so it slips less as it engages, then back on the gas again.

As far as stall, the factory ones are high stall for I6 and 302/5.0 applications, and low stall for 351's. If yours was from a 351 you might look for one from a 6 or 5.0 to get your increased stall. Probably not dirt cheap in any case, though.

David