Flyingfrog, I had my heads off last winter for the same reason. I read that if it hydrolocks you could possibly bend a connecting rod.
You can probably have the heads off in 2.5 to 3 hrs, I was using a air ratchet for take down, not for build up. I had one cracked head that had to be replaced, that was the one smoking badly, the other side was resurfaced and all the valves inspected and replaced as needed.
Replaced the fuel lift pump while the head was off, gives a lot better access.
Replace all gaskets, and all rubber hoses. Had the injectors rebuilt, new open plane intake manifold.
Had exhaust manifolds resurfaced, new gaskets and donuts.
Build up was about 4.5 hours outside in 30 degree weather.
Copy all the pertanent pages from the TM and keep them in the engine bay for reference. Well worth the effort I would not hesitate to do it again.
If you are getting steamy smoke when you take off your oil fill that is water and you may see a white film on the cover , that is oil and water mixing.
Mine cleared up after 2 oil changes and a few hundred miles, you may also want a new cdr valve.
And remember boys and girls, The first rule of owning a CUCV " If its rubber replace it, if its electrical clean it."
