Easy to do , I do it all the time in my clapped out '49 shop truck .
Your steering is very wrong as it _should_ steer just like power steering (serious) so : jack up the truck and block it so the wheels & suspension is hanging loosely in the air (jack stands under frame , dig ?) grab your manual grease gun and some fairly clean rags , scoot underneath the truck with a flashlight and begin greasing all the various Zerk fittings , they're a LOT of them , many will be buried or hidden under globs of old grease & dirt so scrape off all the old clumped up gook , any Zerk doesn't want to take the grease , _STOP_ and go get a propane plumber's torch , heat up the offendeing Zerk fitting a little bit untill it'll take the grease , always grease untill you see fresh grease mushing out elsewhere . wipe up the mess each fitting leaves too .
Turn the steering back and forth as you're greasing the king pins and pivots to ensure good grease spreading .
Now , drain & refill your gearbox and rear end , top up the steering gearbox with OIL ~ never , _EVER_ use grease in there ~ there is a square headed filled plug on the top of the box , sometimes the factory fil plug with Zerk fitting is still there but DO NOT shoot it full of grease ! . if it leaks badly (common) you can use a funnel to fill it with any typ of " Motor Honey " like STP of Bardhal
as this will lubricate it O.K. and leak much slower .
The output seal is listed in older posts , look it up along with how to adjust the steering box if needed .
Don't tour on really old tubes or dry rotted tires , if the tires are O.K. but old , at least have new tubes fitted and keep the pressures up as the tires will heat up on long drives , this is what causes most blowouts : low tire pressures .
Adjust the valves , set points gap or dwell then the ignition timing , HOT change the oil and you're good to go .
Remember , this old truck will go around the world @ 45 ~ 50 MPH but it'll blow up quickly if you wail on down the highway floating the valves .
Have a good trip and take some pix .
-Nate
