Yep - do it now, its not going to get better on it's own. When you swapped your hard parts to the new case you did check all of the clearances? I mean it's basically a rebuild at that point with a soft kit. Reputable converter builders flush out the units with a flushing machine (even my local trans builder has a converter flusher) and normally bolt up the units to a mule engine for test. Leaks are usually done with an air adapter and water. Before reinstalling the converter either get it flushed locally or do it at home. I have poured mineral spirits in, sloshed it around good and then let it sit upside down on a plastic bucket to drain - sometimes over night. I repeat until I am satisfied that nothing else is coming out. Normally you might see a little bit of what is in the pan the first time, any more than that raises a flag for me. Last - how much clearance was there between the converter mounting lugs and flexplate during installation?