Intake manifold fabrication

Yesterday I started intake manifold welding, please keep in mind this is about the second time I have tried to TIG weld aluminum and its my first time trying to weld a thick material (3/8") to thinner material (1/8"), I had many problems, nothing that won't be cleaned up. Also I found out from my boss a way to get a better weld when welding materials with substantial thickness difference (preheat the thicker material with a propane torch), which I will be trying out tomorrow, so I hope it helps with welding quality and speed, so onto the pictures. What you are seeing is the 3/8" plate that will get welded to the intake plenum, with the trumpet style intake runners that should speed up air velocity, the curved entry to the intake runners should also the airflow into the ports and keep runner turbulence to a minimum. After this I will be welding the runners to the intake manifold flange (which is 1/2" aluminum) and after that I will be welding on the intake plenum.