Water coming out of my exaust water vapor and water reserve has to be refilled often

Sounds like a bad head gasket. You should be able to look at your sparkplugs and at least determine which bank of cylinders this problem is coming from. Then you only need to pull off 1 head.

Now there are many new chemicals which plug leaks, and some work and some do not. For a head gasket you need something to handle a higher pressure than is found in the Radiator. The correct repair is replacement of the head gasket and/or Magnaflux the head for cracks.

Stuff like Barrs leakstop is not as effective as some modern chemicals are for what you have as a problem. Expect to pay $12 to $18 for a modern chemical and follow the instructions. I am thinking about 1 chemical I have seen which requires you to drain the Radiator and flushing the cooling system AFTER the chemical is added.

You have an older, easier to work on truck. Be sure to check the compression after you inspect the plugs. You may want to have a Valve job on that bank while you have the head off.

Unfortunately, it sounds like you have a cracked block. To verify this, you can buy a test kit at most autoparts stores.