When I'm cruising down the road, I hear a whining/whirling/howling noise as soon as my foot touches the pedal and stops as soon as I'm off of it. After doing some searching on here it seems like it could be the front pump or planetary gears in my 727. Is there any way to distinguish the two without pulling the trans first? If it were the pump, would it not whine in Park since the pump doesn't operate then? What else 'could' it be? I thought maybe it was a torque converter bolt hitting the inspection plate but it makes the same noise with the plate removed. Converter is new also.

The trans was used but had been beefed up for drag racing. I understand sometimes aftermarket parts can be noisy, could that be it? The trans shifts fine and otherwise doesnt have any problems. It has a deep trans pan and is full according to the stock dipstick.