I'm an insurance agent in NV, though its been years since I've done personal lines. Phil is right to ask your agent and I will add read your policy BEFORE you expose your assets.
Start in the table of contents, and read the definitions, of terms like Other Vehicles, Replacement Vehicles or Substitute. Many policies consider trucks commercial vehicles (and vans too for that matter, depending on model), or the reason that you are using it as a replacement is restrictive. If excluded, it may be an easy fix to add in with an endorsement for little or no charge, but you have to do it before you leave.
If you are considering relying on your own coverage for physical damage to the truck, also proceed with caution, for above reasons, but even if it's covered, they have a process that takes time. It can take anywhere from 48 hours to months to adjust a physical damage claim. But the rental company will want their money immediately.
I'm not trying to to be pessimistic, it's actually my preferred mode of transpo. I empty it out and turn it into a lovely home. I can't afford it this year.
The Liver's End ~ Where the locals go.