Ron, run the car on a good 1/4 mile track to get good data before worrying about the converter. The 1st time I went out with my car I went to an 1/8 mile track with crappy tires. My shift light never went off and I came right home and made a thread on Moparts about my converter. Everyone suggested a good 1/4 mile test, I bought new tires and went to a 1/4 mile track and all was fine, only about 5% slip.
It's also hard to judge anything on the street, I know my car is an absolute handfull on the street, cannot even try to use 1st gear.