I believe I'd go with a little larger-diameter converter, maybe an 11" if it's available. The diameter of the converter directly affects the stall speed, and the centrifugal force on the fluid affects the spin rate from the "pump" section of the converter to the turbine, which is splined to the transmission input shaft. In between the two is the stator, which redirects the direction of flow of the fluid and allows the unit to multiply torque. Once the input shaft starts to move, the torque boost goes away and the converter acts similar to a manual clutch. All torque converters have a 10% RPM slip built in which cannot be engineered out of the design. This is why some converters include a manual clutch that applies at highway cruise speed to make them more efficient. There's nothing new about that idea- - - -the 1949 Studebaker automatic transmission and the 1955 Packard Ultramatic transmission both had a lockup clutch built into their converters. All GM did in the mid-1980's was put a computer in the game.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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