I think a case in point is the blocks. Chrysler cast a lot of blocks in '66 apparently thinking they were going to sell a lot of Hemi cars (probably due to the development team lying to management). Didn't work out that way with the result that '66 castings were being used all the way into 1968 production.

Since they knew that 71 was the last year for the hemi a car could have earlier date items like exhaust manifolds. They were just using up as much remaining stock as possible.

Update: I was able to locate the original owner of the car the manifolds came from. He remembered giving the manifolds to me which really surprised me after all these years. He said he bought the car off a dealer lot in Littleton, Colorado in November of 1969. He said he has the build sheet and will send me a copy when he finds it.

What this means to me is that even giving a month delay, the manifolds couldn't have been cast later than about September of 1969. It will be interesting to know the SPD when he finds the build sheet. More to come.

Hi guys. Don’t have an answer to the date code issue but I am attaching a page from a Chrysler booklet I obtained from 1975 while working at the Chrysler Indianapolis Foundry where the production Hemi blocks were poured. There were four Chrysler Foundries at the time & Chrysler Fostoria Foundry poured grey iron exhaust manifolds. Don’t know if they produced the Hemi manifolds or not but thought I’d add this to the conversation. Hope the picture comes out ok as I’m sending it from my iPhone & can’t see if right side up or not.
Tom Kelly

Is this August 7th 1967?