[Mr70]

Those were cast at the Saginaw,Mi.foundry.
I have a few like that & are actual assembly line parts.
They date coded their components differently then Tonawanda.
E stands for May.
07 is the day.
0 is the last digit of the year casted,1970.
I think you mean CFD,which stands for Central Foundry Division.
The Saginaw foundry provided mostly Flint-(i.e smallblock),with it's components,but Tonawanda-(i.e.bigblock),also borrowed from them too.