Hey if you bring that down to my shop in canton, oh i can tig weld that up for you. I have made some manifolds, it quite a fun experience not to mention the ammount you can learn. Looks like you are using some flux-cored wire, correct? It should hold up fine, it just won't look as good as if it was tig welded together. Looks like a good start though, have fun with the wastgate if you have a free float turbine housing, i used a vertial milling machine to cut out the wastegate port after i finished welding up the entire manifold. Oh and one other thing make sure that you get some flat stock material (1/2" works well) and bolt it to the flanges to prevent some warpage, obviously after you weld it up machine the flanges down so they can seal properly. Good Luck!