Can a 13B Carb Intake Manifold be made to fit a 12A.
 

I'm assuming you can do the same as with the turbo exhaust manifold and alter the mounting holes, however will the ports be off so bad that its not worth the effort. Have a chance to pick 1 up and wanted to know. Thanks.

You can find adapter plates that will move the hole pattern and ports, but a 12A carb manifold is a pretty easy thing to come by. You can redrill a Nikki manifold to run a Holley, or find different lower manifolds if you're running a side-draft.