How does the fluid level look?
I have a 2500 stall converter in my 91 with the 454, and I can hardly tell the difference between it and my stock one in my 92 that has a 350.
The fluid should circulate through the entire trans and converter. The reason for putting some in the converter it to allow you to put as much in the trans before ever moving the innards. There is a vent at the top, and if you put more than 6 quarts in the case before pumping it around, it will weep out of the vent. Once you turn the trans over, you will have to add a lot more (about another 6 quarts) of fluid for it to get near the dipstick mark. If you have an additional stand alone cooler, you may even need more.