Driveline vibration 

@lt1snail That depends on where you put the jack stands. If you put them under the body, yes you are right. But I put them on the axle housing so the rear suspension is still supporting the car.

From that leaky rear end, it's say your pinion bearing is gone.

@unkajah Have not done anything with the car yet. It is getting a completely new rear end (8 3/4" with sure grip) and new axles to go with it So that might fix it.

At the trans. end where the driveshaft connects ,check for looseness or worn out ball and trunnion.

@unkajah I am not familiar with GM components (I'm a Mopar guy). My Dart is getting 3.23 gears. For Mopars there are two types of classic sure grips (what GM calls "Posi"), the cone type or the clutch type (power lok). The general consensus seems to be that the clutch type is better.

I'll tell you exactly what's going on. I heard that exact noise in my 65 Plymouth. The needle bearings in your ball and trunion are dry, broken, and ready to completely give out. Probably, the steel balls that the needle bearings go into are cracked or broken too. Don't bother fixing this driveshaft. Call Driveshaft Specialist in San Antonio Texas and order a new one from them. Best thing I ever did.

The driveshaft has a lot of runout. Pull it and have it trued and balanced with new UJoints and you will be good to go.

You have your car/truck on jack stands so that will already throw your u-joint working angles off.

rear tires balanced?, u joints turn free?, driveshaft balanced?, check pinion for slop, may also be a pinion bearing, or shimmed incorrectly, check make sure angles are same from dshaft to pinion and dshaft to transmission

there is oil all over the back diff thats where your issue is at

@mherbold I am doing the same thing to my car this summer. I have a 8.5" axle from a 1974 Nova, that I am going to use for the camaro.. I am converting it to disk brakes, I am still trying to decide what Posi to use, True-trac, or eaton clutch type. or something else. I am planning to use 3.42 gears. what do you recommend?

I know your video is from 09, did you ever figure it out, from what i can see, it could be a bent axle.. the left rear shock absorber is moving a bit.. that left axle could be bent/twisted inside the housing. let me know what it was if you did fix it. I have a 67 camaro that i believe I have the same problem.

i think your exhaust is hitting your driveshaft

@MileyCyrus192 lol, appears to be 2wd though...

tengo una kamio neta for f 150 kuando esta apunto de entra el kambio bibra pero si le piso al gas no bibra

Line up your yokes on a flat table, you look like you are out of phase.

ke pudeser la trasmisio la bara o el diferensial