Weird tapping sound from TKO

[DarkoNova]

Don't remember if it did this before as I haven't driven the car in 3 years.

Anyway, rebuilt the engine and rear end and converted to a hydraulic clutch using an American Powertrain setup. If I have the car in neutral and rev it, there's no tapping. But when I drive it, there's a distinct tapping/rattling that gets louder as the rpms increase. Is this the infamous "rocks in a can" sound that I've heard people complain about TKO's having?

I took a short video while driving that shows the sound. I'll try to upload it in a second.