I ran a Corvette converter in my 90 Caprice for a while. It had a 2200 stall, and was real fun on the street. Converter companies rate the stall at flash stall. Which is different then footbrake stall. This means that the 2000 stall number is higher then the RPM that the engine will make before it will start to spin the tires or start to develop too much heat which will contribute to trans/converter damage. There is nothing you can do to the converter you already have to change the stall, or get better performance from it. You can change the converter out with a higher stall unit. The best thing you can do is to call a company that builds converters and let them help you decide what stall would be most beneficial to you on your particular application. Also, your lockup speed seems kind of high. OD transmissions are usually in lockup around 41 to 46 MPH, in third or fourth.