340-360 exhaust manifolds

Anybody tried to fit the late model magnums from the trucks on the early A bodies? From what I have read, they are as good as the good 340s. I helped a friend put a set on a 77 or so Ramcharger, but there was scads of room to work with there. We can pick them up at a very reasonable price here, have a set myself I am saving. Paid $100.