Something is out of balance. Wheels, tires, driveshaft, firing order, torgue convertor? Get someone to drive along side and see if any visible signs can be found. You have to have a starting place.
it will probably be 3.73
yes, you may have to do some fabrication on the crossmember to the frame but it will bolt right up to engine.
Probably around 3800-4200lbs
Do you have automatic locking hubs on the front axles?
Yes
yes
Yes
Yes there the same.
yes it will, same thing.
It sure will, with no problems.
Yes it is the same thing.
There are 6 bolts that holds the transmission to the engine.