This kit, and several others, has two long air ducts on the floor of the hull. They run all the way under the engine to the rear wall. In some kits they are molded into the hull base, and in others they are separate parts. Here is an extract from Trumpeter's 1/16 instruction sheet; I have pointed out the two ducts.
But the "Late" version of Tiger, and the later "Mid" Tigers, didn't have both ducts. They were part of the original submersion system, providing air from the snorkel. But all submersion equipment was deleted from the Tiger in mid 1943.
This is a "Late" Tiger hull and we can see what happened to the ducts. The thinner one was completely eliminated. The wider one is still present, and it still connects to the gearbox housing at its front end, but its rear end only goes to the fan connection. As I point out on the photo, the duct doesn't reach the firewall.