Nova exhaust manifold cast dates? To early to use?
 

My 72 Nova SS was built in the 2nd week of Feb 1972. I am looking for the correct exhaust manifolds with the correct cast dates. I found a good pair but the cast dates on these exhaust manifolds are J-71 or October of 1971. So these cast dates are about 3 1/2 months cast before my Nova was built in Feb of 1972. Are 3 1/2 months cast ahead to early for my 72 Nova built in the 2nd week of Feb 1972? Please let me know.