Why does it feel like my 1989 chevy suburban is having a hard time climing hills and blowing out trans fluid it is a 4by4

There are MANY reasons why a car of that age will lose power, not the least of which is engine wear and "blow-by" (a term used to describe the loss of compression past rings and valve seals, usually accompanied by a loss of engine oil).
If your vehicle is burning crankcase oil, or if you remove your oil cap while the car is running and feel air coming out of the oil fill, your engine is really worn and will probably have a hard time going up hills.
Also very common on vehicles of that age is rust in the fuel tank, which will clog the pickup screen (or "fuel sock"), and also clog the fuel filter with rust particles. A good place to start is replacing your fuel filter, and see how much RED is visible. (Any RED you see in what comes out of the input side of your fuel filter is rust from the gas tank.) If you get red gunk out of your old fuel filter, you'll definitely need to clean or replace your fuel tank and replace the fuel sock as well.
Next thing to check is the last time the vehicle had a major tune-up. Was it over five years or 25,000 miles ago? Go ahead and do a major tune-up. (Do all that applies to the engine you have: Plugs, wires, cap, rotor, coil, coil packs, throttle body clean, static timing adjust, ODB code clearing, and complete fluid change INCLUDING transmission AND both differentials).
As far as the vehicle "blowing out transmission fluid," I can't answer that at all, not knowing where it's blowing it out from.