I have a 72 LeMans with a 400 sbc and TH350. The transmission seems to makes a whirring sound in park and neutral, and also through all gears. It does this regardless if the transmission is cold or warm. I not sure what type of torque convertor is installed since it's not the original drivetrain. I checked the fluid and it was at the proper level, with fluid hot and engine at idle. Thanks for anyones help on this, it's greatly appreciated.