If it's a street driver, I would recommend a good set of stock exhaust manifolds (like the 68-70 240 manifolds).
Or use headers that do not hang below the k-frame as they will eventually get crushed and not flow worth a dam...
I used to run headers on the street, but went back to stock manifolds.
Less starter and installation issues also. Sometimes headers are difficult to work around, or have too much heat and burn up starters.