Exhaust Manifolds

Depends if an early or late A body, and whether it has power or manual steering.
Late A with manual steering with a cut back column collar, clearance grinding on the manifold for column clearance, and possibly a change to a u joint and/or angle grinding the manifold mating surface. Each car will have a different tolerance stack.
Are they a bolt in? Hell no.
I wouldn't mess with them. From what I've read I wouldn't even use 350 manifolds