question about exhaust manifolds

[rustythumb]

was looking at a friend's '41 merc the other day & noticed that it's left manifold has it's outlet further forward than my ford manifold. [evidently to clear the steering box] the ford parts book seems to show the same part # for ford & merc. can any one explain this? also, does anyone know of any photos of all the different stock exhaust manifolds made by ford? thanks!