Even though your truck may be nickel and diming you at least you are not paying a note on a $30,000+ Silverado. I would also say your insurance and property taxes are a lot lower also. Just hang in there and your truck will pay you back. In the end you will still be able to haul and ride just as well as those with newer trucks.
The basic stuff like the frame,engine and trans will last for decades. If you have not done so already, put a complete, new distributor in your truck becase it will fail and leave on the side of the road (the wires to the pick-up coil break). I have a 78 Scottsdale that was bought by my father new and I still drive it everyday. Origianal engine, trans, rearend and front /rear suspension. Better than your favorite pair of blue jeans. My gas tank rusted out last year so I feel your pain.
John