91 zeee

OK, so I just built a motor for my 91 Z. I have driven it about 70 miles since the rebuild (not hard miles). All of a sudden tonight the car developed a rattle. It's present in gear or out of gear. At first I thought maybe it was an exhaust leak or...way worse....a bottom end noise on new motor.
Well..... as it turns out it sounds like it's coming from the torque converter. I checked the TC bolts and they are tight. I checked the starter bolts and checked to make sure the starter wasn't getting hung up...all good. I remember using Loctite and torquing the flex plate bolts (flex plate is new and came with the Eagle rotating assy).
This is where it gets weird......when I shut the motor off, as it slows to a stop I can still hear the rattle. Any ideas????