question about converters

New motor has been in @ 4 weeks now. Been driving the car around to get a feel for things etc.. We have an 11" Dynamic converter installed, and yes Im sure I made the wrong choice. The converter is basically "locked in" right from idle. You can hit the pedal to the floor from idle @ 850-900 rpm and barely haze the tires. Very odd, the motor just a few short weeks ago pulled 430HP and 440 Tq peak on the dyno at the crank with undersized 1 -5/8" headers and the carb a bit lean. (The factory 275 hp was enough to roast the tires..) Even from a roll, say at a road speed of 50mph you can mash it and the responce is poor. Anyhow, question about the converters, does anyone know what the factory rating stall speed was on OEM torque converter? Flash stall speed?? Any experience with comparisons to a modern Dynamics 11" to the stock Hi-po 340 converter '68-70?? Thanks tom