Tires, Towing and some other stuff

1994 K1500 ext cab sbox
383 cid TBI injection stock computer and holley 670 throttle body
stock exhaust manifolds
built 4L60E transmission
semi float 14 bolt  and 4:10 gears
35x12x18 tires 18x9 aluminum rims
stock brakes

I plan on towing about 7500-8000 lbs.
It will be my 27 foot (31 feet from tongue to bumper) camper which weights 6666lbs and I figure an extra 1400lbs for passengers and cargo

I would like a set of either BFG mud terrain's or Goodyear MTR's both in 35x12.5x18
I dont mind the road noise
Will they handle my towing duties cruising down the highway doing 50 to 70 MPH?
I also have a lockrite locker for the 14 bolt semifloat. Will the locker handle the highway?
Does anyone think I am towing too heavy?
How about adding some airbags to the rear?
A class 4 hitch is in the works as well.
am i missing anything?

Your input is greatly appreciated.  

Make sure you get the proper ratted tires. I am thinking your application calls for "D" weight rated tired.

The 4L60 was designed for a GVWR vehicle of 6000lbs (it is also known as a 700R4 and 4L60-only difference is it has an electronic shift control vs the TV Cable).

Air bags are not a bad idea. It would help level the truck out when loaded.

I don't know anything about the lockers. If they are a selectable kind then they should be just fine I would think.

Hope this helps a bit.  
'91 K1500 (Stock)
LT285/75R16
Play hard! Play soft! As long as you are having fun!