'70 142 lowered 1.5"...stock M40 wobble stick, 15' wheels, 60 series tires

Horrible screeching scrunching scrutching sound on decel in 3rd and 4th, not in 1st and 2nd, sometimes while feathering in cruise, doesn't always go away when you reapply throttle...seems unrelated to engine speed, comes from under the car...not really from driveshaft area, just behind front seats sorta

Spider gears or pinion bearing?

Also terrific driveline vibration over 4000, at least I think its driveline, seems to come from transmission, but I had it rebuilt with new main brngs and seals...driveline was balanced, but center bearing looked OK, so was reused.

Could any of this be pilot bearing...I put in what was recommended a little NSK 201RR ball bearing?

Where do I spend money first?

Ron