I am trying to figure out how I field the Gobsmasha & Lung Bursta in the Ghazgkhull's Warhorde or are they not allowed? What are they called?

I would think they are armored vehicles, but the only thing I see listed are battlewagon, flakwagon and gunwagon, which are all transports. I am guessing they are gunwagons.

Yep, gunwagons.

Yeah, gunwagons are the best bet. Gunwagons have a pretty limited transport capability - it's not hard to imagine five orks hanging on to the side or squeezing together in there and jumping out the hatch.

Gunwagons it is then. :-)