question about converters

I called them earlier this afternoon. Spoke to Shawn. Im not 100% sure what the specs are on this 11"..Im guessing stall speed @ 2500 advertised, not sure what the flash stall is. Believe me, the question has come up if there is something not right about this converter. Shawn says, based on the cam specs and some dyno info the converter "is not matched up".. But to be locked up from idle? I saw in last months Mopar Muscle the guy with stroked 70 Duster running LOW 12's-NO traction at all with a "stock oem" converter.
Same distributor, coil, plug wires, harness and ECM used on Dyno thats in the Duster.. Only components added: full exhaust and trans/converter