Rumble/vibrations from around front differential and under floorboards.

I started a thread a while back with not very much help. I have a 2000 Tacoma 4wd with 172,000 miles on it, it also has Chevy 63" rear leaf springs and toytec 3 inch lift Bilstein shocks in the front. I have replaced the cv axles and did the ecgs bushing swap. I have a terrible rhythmic rumble that happens for a few seconds after letting off the gas or with very light pedal pressure (not enough to provide propulsion, just enough so the engine rpm doesn't slow the vehicle). This noise happens when going faster than about 40mph. I have read that the taco vibes at 20mph can be solved by carrier bearing drops and leaf shims, but there isn't any noise from the rear driveshaft. I do have that vibration as well haha but I'm trying to deal with the most noticeable issues first. The transmission also had a rebuild on it not very long ago.

 

Is there a change in the rumble when you engage 4wd?

 

seems to go away a majority of the time, but sometimes is very faint in 4wd

 

Ok just test drove it and definitely still there in 4WD