1970 and 1971 Z28 winters intake letter stamp meaning?

[Nasblu]

Originally Posted by BCreekDave

Seen this asked before on NastyZ28.
No good answer I have seen. It is on my original intake, but is I think its a number. No correspondence to a date. My guess is that due to it being a stamp and not a casting that it is done post molding and relates to a machining operation. Probably not warranty replacement. I've seen it on too many engines. Unless they replaced many intakes and I think we would have heard about that.

That was me asking over at NastyZ28 as well never did get an answer.