This is basic & old hat for most of us, but let's back track a little in case the OP isn't aware.
Ford used casting #'s starting with B in the 50's, C in the 60's, D in the 70's. (you see the pattern). The second digit was a number for the year in the decade. C6=1966, D2=1972 etc.
Many parts could have a casting number/part number that seems incorrect, ie too early by 1, 2, 3, or more years. This many not be a problem as many parts were cast/made and used on later cars.
What you look for are #s later than the production year of the car. They would very likely not be original.
Also, concerning 352, that was a truck engine, but don't fret. I had the same fear 20 years ago when I saw that on my 428CJ block. FE engines of that era all had that 352 cast into the block. It's scared the bejeezus out of countless car owners!
'69 B code Sportsroof Restomod in Progress. Factory AC, PS, PB, DLX int, fold down, tach dash added, T5, & on & on.