If you drained pan changed filter you still about 7 or 8 quarts of old fluid in your torque convert it's not to hard to change 3 or 4 quarts of new fluid is going to mix with 7 or 8 quarts of old dirty fluid. steelcat 70 XR7 ragtop
If I remember my FMXs correctly, you can take off the inspection cover on the engine/transmission block plate. Turn the engine over slowly and you'll find a factory drain plug for the torque converter. There's a hole in the flex plate that the head of the drain plug can be seen through. Once you drain both the converter and drop the pan, it should take about 9-10 quarts. Best to start checking after seven or so.