Left Exhaust manifold for 360 Book shows 3614 367 or 3751 083 or 3614 368, I think

You need a drivers side manifold shaped like the one in the bottom of the pic in post #1. All A body drivers side manifolds are shaped like that. The one in post #9 is a drivers side B or E body manifold, and won't fit an A body. They hit the steering column/shaft.