Ever since doing a T-5 swap in my '52 there has been an almost constant grinding/rubbing noise that speeds up and slows down with the truck. It is there with the clutch pedal pressed in and let out. The transmission shifts/drives fine and there were no metal flakes in the fluid when I changed it. The driveshaft was cut and balanced. What could this be?

Some things that I am thinking... input shaft bearing is bad, TO bearing is adjusted to rest on the fingers, TO fork ends should be round (welded flat because I thought this was wear), or the rear U-joint needs to be greased (I packed it when I put it back on but never shot it on the zert)... any thoughts?