Installing 1972 340 manifolds 3614368 (driver's side) and 3418623 (passenger's side, center dump) - Any Exhaust Pipe Clearance Issues to be Aware of?

I'll prolly end up having a local muffler shop mandrel-bend the pipes for me. They should also either have in stock or be able to fab up some pipe-to-manifold flanges.
Never seen a local muffler shop with a mandrel bender. They are pretty high dollar. I don't think it would matter much on a fairly mild build.