Ioverlander
ioverlander.com is far more than camping and also has a lot of info about border crossing procedures that is hard to find anywhere else.
From all the information published on a few specialist overlanding facebook groups and forums dealing with the Americas and from my own experience (but none in Central America), it is quite obvious that the personal danger posed from criminal acts by travelling through the entire Americas is absolutely not worthy of consideration, BUT some of the border crossings need careful attention. For instance there is one country in Central America where if you are heading south through it, you can't return north through that country within 90 days. Possibly some exemptions or procedures to mitigate it but a few get caught out by the rule.
iOverlander does have a BigRig suitability estimation but as Brian said, our big rigs tend to be a bit different. Man truck up to 8'6" wide, 12' high and up to 30' long, but ranging down to bicycles too
Just a few overlanding vehicles down in South AmericaOne comment relevant to the OP is that many countries do not permit permanent importation of vehicles under any circumstances or only if they are less than 2 or 5 years old and the valuse they figure the import taxes on are what the vehicle would cost brand new in that country