That's the EUN (engine unit number what I call it).
Your POP says 0475581 which is correct so the engine code YD on it is wrong.
The 'c' is because the 1st zero is chipped and it looks like a partial zero or 'C'.
So on your engine it probably has the chipped zero.
Also on your POP which is Canadian, it has the engine code and the eun like the earlier year POP had. I think the US POP did not show it in 1970. (and on)
Which is why I thought it was a 400 2bbl, since a US made car would not have that info.
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John Wallace - johnta1
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