Early head question.
 

I have a set of C3AE 289 heads. The bolt holes on the ends of the heads where the intake bolts to the head are in the same location as late heads, like the E7TE, but they aren't quite the same. They aren't on the same surface as the middle 4 intake bolts. When you bolt an intake down to these heads the 4 corner bolts are exposed to the weather. Did I explain this very well? LOL If you understand what I mean, what year did they start making them like the late style heads?