Welcome again Peter. On most of the cars that become gassers, they have full thicker metal frames to weld to. So they are pretty stout. But when you are building a unitbody car (no seperate frame) you need to reinforce the welded area. Just like roll bars/cages it requires you to sandwich steel plating top and bottom of the flooring. This disperses the stress across a larger area and saves the thinner metal. Anything is doable if done right. Mark L