This was another big factor I was considering, but I'm wondering if this is a concern with all modified trucks? If I bought a stock truck, modded it, then totaled it, you lose all the $ from the mods?
Bingo.
Unless your policy specifically states that it covers stuff like that, then your insurance company is under absolutely zero obligation to pay for it, regardless of what is told to you by the guy making a commission on selling you the policy.